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Pathophysiology of Cushing's Disease

2009-11-12T04:26:00.000-08:00

Cushing's Disease

The term "Cushing's syndrome" is used to describe a condition resulting from long-term exposure to excessive glucocorticoids. The syndrome is most commonly caused by the therapeutic administration of exogenous glucocorticoids. The term "Cushing's disease" is reserved for Cushing's syndrome that is caused by excessive secretion of adrenocorticotropin hormone (ACTH) by a pituitary tumor, usually an adenoma.

Cushing's disease is a disease in which the adrenal glands overproduce certain hormones. Another medical term for this disease is hyperadrenocorticism. The adrenal glands produce several vital substances, which regulate a variety of body functions and are necessary to sustain life. The most widely known of these substances is cortisol, commonly known as cortisone. Either deficient production or excessive production of these substances may be life-threatening. Cushing's disease is a form of Cushing's syndrome that is caused by an ACTH secreting pituitary adenoma. About 10% of pituitary adenomas secrete excess ACTH. This elevated ACTH in turn stimulates the adrenal glands to produce excess cortisol. This disease process is called Cushing's disease (named after the famous neurosurgeon, Harvey Cushing).

Cushing's disease is responsible for roughly two thirds of the cases of endogenous Cushing's syndrome. The remainder of the endogenous cases are caused by ectopic ACTH-secreting tumors and primary adrenal neoplasms. Cushing's disease occurs most frequently in women of reproductive age, but it can affect males and females of any age.

There are three mechanisms by which this disease can occur. Regardless of the cause, the clinical signs are essentially the same. It is important to identify the cause, however, because the various forms are treated differently and have different prognoses.

Pituitary gland tumor. The most common cause of Cushing's Disease (85% of all cases) is a tumor of the pituitary gland. The tumor may be either benign or malignant. The tumor causes the pituitary to overproduce a hormone, which stimulates the adrenal glands. Excessive cortisone secretion results. The pituitary tumors in Cushing's disease are usually microadenomas, which, by definition, are 10 mm or less in diameter. Microadenomas generally do not cause symptoms by local mass effect. These tumors are most often discovered when clinical manifestations of hypercortisolism resulting from hypersecretion of ACTH prompt an appropriate diagnostic work-up. Occasionally, microadenomas are found incidentally during imaging performed for other reasons.

Macroadenomas are uncommon in patients with Cushing's disease. These tumors cause mass effect when their size exceeds 15 mm in diameter. Suprasellar extension and optic chiasm compression, local bone erosion, cavernous sinus compression and panhypopituitarism may occur as a macroadenoma enlarges.

Adrenal gland tumor. Cushing's Disease may be the result of a benign or malignant tumor of the adrenal gland. If benign, surgical removal cures the disease. If malignant, surgery may help for a while, but the prognosis is less favorable than for a benign tumor.

Iatrogenic. Iatrogenic Cushing's Disease means that the excess of cortisone has resulted from excessive administration of cortisone. This may occur from oral or injectable medications. Although the injections or tablets were given for a legitimate medical reason, their excess is now detrimental.

Patients with Cushing's disease usually present with one or more signs and symptoms secondary to the presence of excess cortisol or ACTH. The clinical diagnosis must be based on the presence of one or more of these findings (Figure 1 showing Multiple wide striae on the abdomen of a patient with Cushing's disease.), because the syndrome itself has no true pathognomonic signs or symptoms.

The most common symptom is sudden weight gain. Obesity, usually with a central distribution, is the most frequent sign. Any sign or symptom of cortisol excess can develop initially, but muscle weakness, bruising, hypertension, facial rounding and plethora eventually occur. Hypertension is likely to develop in patients who are more than 40 years of age.

Cranial nerve III (oculomotor nerve) palsies are less well recognized, but they may occur in up to 25 percent of patients with pituitary macroadenomas and may be the lone presenting symptom in patients with pituitary adenomas. Pituitary tumors infrequently affect cranial nerves IV and VI. The mechanism for oculomotor palsies is usually direct compression by the expanding tumor as the nerve passes through the walls of the adjacent cavernous sinus.Noncompressive cranial nerve III paresis has also been reported in patients with Cushing's disease.

Another presentation or complication of Cushing's disease is opportunistic or bacterial infection. Immunosuppression resulting from corticosteroid excess is usually thought of as a cellular immune deficiency that increases the risk of opportunistic infections (Cryptococcus neoformans, Candida species, Norcardia species and other organisms). Eight of the 12 cases were complicated by bacterial infections. Subsequent case reports have further emphasized the frequency of bacterial infections in Cushing's disease.

A number of tests are necessary to diagnose and confirm Cushing's Disease. The primary one is the ACTH Stimulation Test. If it does not confirm the diagnosis, the Low-Dose Dexamethasone Suppression Test is performed. Other tests are needed to decide which form of the disease is present. An ultrasound examination can be a valuable part of the testing process. This permits us to visualize the adrenal gland tumor and determine its size. Although some of these tests are somewhat expensive, they are necessary.

Treatment is surgery to remove the pituitary tumor, if possible. After surgery, the pituitary may slowly start to work again and return to normal. During the recovery process, cortisol replacement treatments may be necessary. Radiation treatment of the pituitary gland may also be used. If the tumor does not respond to surgery or radiation, medications to stop the body from making cortisol are given. Untreated, Cushing's disease can cause severe illness, even death. Removal of the tumor may lead to full recovery, but the tumor can grow back.

Pathophysiology of Cushing's Disease

When stimulated by ACTH, the adrenal gland secretes cortisol and other steroid hormones. ACTH is produced by the pituitary gland and released into the petrosal venous sinuses in response to stimulation by corticotropin-releasing hormone (CRH) from the hypothalamus. ACTH is released in a diurnal pattern that is independent of circulating cortisol levels: peak release occurs just before awakening, and ACTH levels then decline throughout the day. Control of CRH and ACTH release is maintained through negative feedback by cortisol at the hypothalamic and pituitary levels. Neuronal input at the hypothalamic level can also stimulate CRH release.

Although the adenomas of Cushing's disease secrete excessive amounts of ACTH, they generally retain some negative feedback responsiveness to high doses of glucocorticoids. Ectopic sources of ACTH, usually in the form of extracranial neoplasms, are generally not responsive to negative feedback with high doses of glucocorticoids. However, some overlap exists in the response to negative feedback between pituitary and ectopic sources of excessive ACTH.

Cushing's syndrome is categorized as ACTH dependent or ACTH independent. This division is convenient for organizing the work-up of patients with suspected hypercortisolism.

Depression, alcoholism, medications, eating disorders and other conditions can cause mild clinical and laboratory findings, similar to those in Cushing's syndrome, termed "pseudo-Cushing's syndrome." The laboratory and clinical findings of hypercortisolism disappear if the primary process is successfully treated.

Dexamethasone, an exogenous glucocorticoid, is used to test for Cushing's syndrome. This gluococorticoid does not interfere with cortisol assays but induces similar physiologic responses.

Hypothalamus - Neuroanatomy Transcription

2009-11-12T03:17:00.001-08:00

CHAPTER 13- the hypothalamus and its connections

Hypothalamus

- Small (about 0.3% of the total brain)

- Controls the autonomic nervous system and the endocrine system

- Indirectly controls body homeostasis

- Lies in the center of the limbic system

- Site of numerous converging and diverging neuronal pathways and through its adequate blood supply it is able to sample the blood chemistry

- Makes appropriate controlling responses following the integration of its nervous and chemical inputs

- Part of the diencephalon that extends from the region of the optic chiasma to the caudal border of the mammillary bodies

- Lies below the thalamus and forms the floor and the inferior part of the lateral walls of the third ventricle

- Caudally, the hypothalamus merges into the tegmentum of the midbrain

- Lateral boundary is formed by the internal capsule

Preoptic area of the hypothalamus

- Area anterior to the hypothalamus

- Extends forward from the optic chiasma to the lamina terminalis and the anterior commissure

When observed from below, the hypothalamus is seen to be related to the following structures form anterior to posterior:

Optic chiasma
tuber cinereum and the infundibulum
mammillary bodies

HYPOTHALAMIC NUCLEI

Microscopically:

- the hypothalamus is composed of small nerve cells that are arranged in groups or nuclei, many of which are not clearly segregated from one another

Preoptic area

- Included as part of the hypothalamus for functional reasons

The nuclei are divided by an imaginary plane into medial and lateral zones
Fornix and mammillothalamic tract- Lies within the plane and serves as markers

Medial Zone

The following hypothalamic nuclei are recognized from anterior to posterior:

Part of the preoptic nucleus
Anterior nucleus (merges with the preoptic nucleus)
Part of the suprachiasmatic nucleus
Paraventricular nucleus
dorsomedial nucleus
ventromedial nucleus
Infundibular (arcuate) nucleus
Posterior nucleus

Lateral Zone

From anterior to posterior:

Part of the preoptic nucleus
Part of the suprachiasmatic nucleus
supraoptic nucleus
lateral nucleus
Tuberomamillary nucleus
The lateral tuberal nuclei

Modern technology: Histochemical, immunochemical and anterograde and retrograde tracer studies—precisely defines groups of neurons and their connections

Most of the hypothalamic nuclei have ill-defined boundaries

Hypothalamic Lines of Communication

Hypothalamus receives information from the rest of the body through:

Nervous connections
Bloodstream
CSF

- The neurons of the hypothalamic nuclei respond and exert their control via the same route

- CSF may serve as a conduit between the neurosecretory cells of the hypothalamus and distant sites of the brain

AFFERENT NERVOUS CONNECTIONS OF THE HYPOTHALAMUS

Hypothalamus

- Lies in the center of the limbic system

- Receives many afferent fibers from:

o the viscera

o Olfactory mucous membrane

o Cerebral cortex

o Limbic system

The afferent connections are numerous and complex
Main pathways are as follows:

Somatic and visceral afferents

General somatic sensation, gustatory and visceral sensations, reach the hypothalamus through collateral branches of the lemniscal afferent fibers and the tractus solitarius and through the reticular formation

Visual Afferents

Leave the optic chiasma and pass to the suprachiasmatic nucleus

Olfaction

Travels through the medial forebrain bundle

Auditory afferents

Not been identified

Corticohypothalamic fibers

Arise from the frontal lobe of the cerebral cortex and pass directly to the hypothalamus

Hippocampohypothalamic fibers

Pass from hippocampus through the fornix to the mammillary body
Hypothalamus is the main output pathway of the limbic system

Amygdalohypothalamic fibers

Pass from the amygdaloid complex to the hypothalamus through the stria terminalis and by a route that passes inferior to the lentiform nucleus

Thalamohypothalamic fibers

Arise from the dorsomedial and midline thalamic nuclei

Tegmental fibers- arise from the midbrain

EFFERENT NERVOUS CONNECTIONS OF THE HYPOTHALAMUS

Main pathways:

Descending fibers to the brainstem and spinal cord

Influence the peripheral neurons of the ANS
Descend through a series of neurons in the reticular formation
The hypothalamus is connected to the parasympathetic nuclei of the oculomotor, facial, glossopharyngeal, and vagus nerves in the brainstem
The reticulospinal fibers connect the hypothalamus with sympathetic cells of origin in the lateral gray horns of the first thoracic segment to the second lumbar segment of the spinal cord and the sacral parasympathetic outflow at the level of the second, third, and fourth sacral segments of the spinal cord

mammillothalamic tract

Arises in the mammillary body
Terminates in the anterior nucleus of the thalamus
Here the pathway is relayed to the cingulated gyrus

mammillotegmental tract

Arises from the mammillary body and terminates in the cells of the reticular formation in the tegmentum of the midbrain

Limbic system (multiple pathways)

CONNECTIONS OF THE HYPOTHALAMUS WITH THE HYPOPHYSIS CEREBRI

- The hypothalamus is connected to the hypophysis cerebri (pituitary gland) by 2 pathways:

1. Nerve fibers that travel from the supraoptic and paraventricular nuclei to the posterior lobe of the hypophysis

2. Long and short portal blood vessels that connect sinusoids in the median eminence and infundibulum with capillary plexuses in the anterior lobe of the hypophysis

- these pathways enable the hypothalamus to influence the activities of the endocrine glands

HYPOTHALAMOHYPOPHYSEAL TRACT

Vasopressin and oxytocin

- Synthesized in the nerve cells of the supraoptic and paraventricular nuclei

- Passed along the axons together with carrier proteins called neurophysins, and are released at the axon terminals

· Here the hormones are absorbed into the bloodstream in fenestrated capillaries of the posterior lobe of the hypophysis

Vasopressin

- Antidiuretic hormone

- Produced mainly in the nerve cells of the supraoptic nucleus

- Function: causes vasoconstriction

- Also has an important antidiuretic function, causing increased absorption of water in the distal convoluted tubules and collecting tubules of the kidney

Oxytocin

- produced mainly in the paraventricular nucleus

- Stimulates the contraction of the smooth muscle of the uterus and causes contraction of the myoepithelial cells that surround the alveoli and ducts of the breast

- Produced in large amounts during the end of pregnancy

- Stimulates labor contractions of the uterus

- Stimulated by the suckling of the nipples by the babies promoting contraction of the myoepithelial cells and assists in the expression of the milk from the breasts

Supraoptic nucleus

- Produces vasopressin

- Act as an osmoreceptor

- Osmotic pressure increase vasopressin increase causing reabsorption of water

Hypophyseal Portal System

Releasing hormones and release inhibitory hormones

- produced by the neurosecretory cells situated mainly in the medial zone of the hypothalamus

- Hormones are packaged into granules and transported along the axons of these cells in the medial eminence and infundibulum

o Here the granules are released by exocytosis onto fenestrated capillaries at the upper end of the hypophyseal portal system

* HPS is formed from the superior hypophyseal arterty, which is a branch of the internal carotid artery

* The portal system carries the releasing hormones and the release-inhibitng hormones to the secretory cells of the anterior lobe of the hypophysis

Releasing hormones stimulate the production and release of

- ACTH

- FSH

- LH

-Thyrotropic hormone or thyroid stimulating hormone (TSH)

- Growth hormone (GH)

Release of inhibiting hormones inhibits the release of:

- melanocyte-stimulating hormone (MSH)

- Luteotropic hormone (LTH)

Luteotropic hormone (LTH)

- Also known as lactogenic hormone or prolactin

- Stimulates the corpus luteum to secrete progesterone and the mammary gland to produce milk

Somatostatin

- Inhibits the release of growth hormone

- Growth hormone inhibitory hormone

Neurons of the hypothalamus

- Influenced by the Afferent fibers passing to the hypothalamus

- responsible for the production of the releasing hormones and the release-inhibiting hormones

- Also influenced by the level of hormone produced by the target organ controlled by the hypophysis

- Should the level of thyroxine in the blood fall the releasing factor for the thyrotropic hormone would be produced in increased quantities

FUNCTIONS OF THE HYPOTHALAMUS

Autonomic Control

Hypothalamus

- Has a controlling influence on the autonomic nervous system

- Appears to integrate the autonomic and neuroendocrine systems

- Preserves body homeostasis

- Regarded as a higher nervous center for control of lower autonomic centers in the brainstem and spinal cord

- Anterior hypothalamic area and the preoptic area influence parasympathetic responses. This include:

o Lowering of the blood pressure

o Slowing of the heart rate

o Contraction of the bladder

o Increased motility of the GIT

o Increase acidity of the gastric juice

o Salivation

o Pupillary constriction

- Stimulation of the posterior and lateral nuclei causes sympathetic responses, which include:

o Elevation of blood pressure

o Acceleration of the heart rate

o Cessation of persitalsis in the GIT

o Papillary dilation

o Hyperglycemia

ENDOCRINE CONTROL

Nerve cells of the hypothalamic nuclei

- produces releasing factors or release-inhibiting factors

- Control the hormone production of the anterior lobe of the hypophysis (pituitary gland)

Anterior lobe hormones include:

- growth hormone

- prolaction (luteotropic hormone)

- adrenocorticotropic hormone

- thyroid-stimulating hormone

- luteinizing hormone

- follicle stimulating hormone

* Some of these hormones act directly on body tissues while others such as ACTH act through an endocrine organ which in turn produces additional hormones that influence the activities of general body tissues

* Each stage is controlled by negative and positive feedback mechanisms

TEMPERATURE REGULATION

Anterior portion of the hypothalamus

- controls those mechanisms that dissipate heat loss

- Stimulation of this area causes dilatation of skin blood vessels and sweating, which lower the body temperature

Posterior portion of the hypothalamus

- Stimulation results in vasoconstriction of the skin blood vessels and inhibition of sweating

- There is shivering, in which the skeletal muscles produce heat

· Normally, the hypothalamus sets the body temperature at 98.0-98.6f when measured orally and one degree higher when measured rectally

· The temperature can be altered in response to extremes in environmental temperatures or in infection

REGULATION OF WATER AND FOOD INTAKE

Lateral region of the hypothalamus

- Stimulation initiates the feeing of hunger and results in an increase in food intake

- Referred to as the “hunger center”

- Bilateral destruction results in anorexia with loss of body weight

Medial region

- Simulation inhibits eating and reduces food intake

- Referred to as the “Satiety center”

- Bilateral destruction produces an uncontrolled voracious appetite causing extreme obesity

Thirst Center

- Area in the lateral region of the hypothalamus that causes an immediate increase in the desire to drink water

Vasopressin (ADH)

- Secretion is controlled by the hypothalamus controlling the osmolarity of the blood by the posterior lobe of the hypophysis

- Causes a great increase in the reabsorption of water in the distal convoluted tubules and the collecting tubules of the kidneys

EMOTION AND BEHAVIOR

- Function of the hypothalamus, limbic system, and the prefrontal cortex

- The hypothalamus is the integrator of afferent information received from other areas of the nervous system and brings about the physical expression of emotion

o Can produce an increase in the heart rate

o Elevate the blood pressure

o Cause dryness of the mouth

o Flushing or pallor of the skin

o Sweating

o Often produce a massive peristaltic activity of the GIT

CONTROL OF CIRCADIAN RHYTHMS

- Controlled by the hypothalamus

- Circadian rhythms include:

o Body temperature

o Adrenocortical activity

o Eosinophil count

o Renal secretion

- Sleeping, wakefulness, although dependent on the activities of the thalamus, limbic system, and the reticular activating system are also controlled by the hypothalamus

Lesions of the anterior part of the hypothalamus

- Seriously interfere with the rhythm of sleeping and waking

Suprachiasmatic nucleus

- receives afferent fibers from the retina

- Appears to play an important role in controlling biological rhythms

- Where nerve impulses generated in response to variations in the intensity of light are transmitted to influence the activities of many of the hypothalamic nuclei

CLINICAL NOTES

Clinical Disorders Associated with Hypothalamic Lesions

The hypothalamus may be the site of inflammation, neoplasm, or vascular disorder because of its deep-seated position
Can be pressed upon by tumors of the surrounding brain tissue or may be compressed as the result of the development of internal hydrocephalus
A lesion will produce a large number of different syndromes
An acute lesion is more likely to produce signs and symptoms than is a slowly growing tumor

Obesity and Wasting

Severe obesity

- Can occur as the result of hypothalamic lesions

- Associated with genital hypoplasia or atrophy

Wasting

- Less common

- Severe cachexia is suggestive of damage to the hypophysis (pituitary gland)

Sexual Disorders

- In children: there may be sexual retardation and rarely sexual precocity with hypothalamic lesions

- After puberty: Patient with hypothalamic disease may have impotence or amenorrhea

Hyperthermia and Hypothermia

Hyperthermia

- Can follow lesions of the hypothalamus caused by head injury or following surgical operations in the regions of the hypothalamus

- Otherwise normal and has no signs of malaise, which occurs with pyrexia secondary to infections

Hypothermia

- Can follow a lesion of the hypothalamus

Diabetes Insipidus

- Result from a lesion of the supraoptic nucleus or from the interruption of the nervous pathway to the posterior lobe of the hypophysis

- Patient passes large volumes of urine of low specific gravity

- Patient is extremely thirsty and drinks large quantities of fluids

- In diabetes mellitus there is glucosuria

Disturbances of Sleep

- frequent short periods of sleep during the waking hours or insomnia in patients with hypothalamic lesions

Emotional Disorders

- Attacks of unexplained weeping or laughter

- Uncontrollable rage, depressive reactions

- Maniacal outbursts

Heart - Cardio Notes for Nursing and Med Students

2009-11-11T07:11:00.000-08:00

**This is an old file I found after sorting out my folders and documents in my laptop. It's a transcription used as a reviewer about the cardiovascular system and corresponding diseases involved. I guess I'll be using this document every now and then, so I suppose I could share it with you.** (shei ^^)

HEART (Cardiologic System)

ANGINA

- chest pain due to diminished O2 supply to the myocardium

- Causes:

a. atherosclerosis – fatty plaque deposits in the intima of the artery

b. arteriosclerosis – calcium deposits in the media f the artery causing hardening

- Types of Angina:

a. Stable (Effort) – ↑activity = pain, relieved by rest

b. Unstable (Pre-infarction) – ↑activity = pain, not relieved by rest nor NTG

c. Prinzmetal (Variant) – pain at rest with vasospasm , relieved by NTG

d. Intractable – continued pain not relieved by NTG

- Characteristics of chest pain:

- Substernal or retrosternal pain that radiates to arms neck and jaws

- Squeezing and heavy tightness of the chest

- Lasts for a few minutes and then subsides

- Precipitating Factors: 5 Es

Exercise

Exertion

Emotions

Eating heavy meal

Exposure to cold

- Diagnostics

a. NTG test – shows relief from pain

b. ECG – reveals ST and T wave changes

c. Thallium 201 Imaging

d. Technetium-99 Imaging

- Nursing Diagnoses

1. Pain related to imbalance in myocardial oxygen demand

2. Decreased cardiac output related to reduced preload and afterload

3. Anxiety related to pain, uncertain prognosis and threatening environment

- Management:

Instruct px to stop all activities

Place in a comfortable position

Give antianginal drugs – i.e. Nitroglycerin

Administer O2

Maintain cardiac output

Decrease Anxiety

CORONARY ARTERY DISEASE - i.e. coronary atherosclerosis

- results from focal narrowing of coronary arteries

- incidence increases progressively with age

Etiology - May involve combination of factors:

a. genetic predisposition

b. metabolic disturbances

c. hypertension

d. altered platelet function à predisposes to plaque formation

Risk factors

- Advanced age

- Obesity

- Male or postmenopausal female

- Sedentary lifestyle

- Hyperlipidemia

- Family history of CAD

- Smoking

- Diabetes mellitus

- Chronic stress

- Chronic oral contraceptive use

- Pathophysiology: Formation of fatty, fibrous plaques on the intima of coronary arteries à Narrowing of the arterial lumen à Reduced blood flow to the heart à Myocardial ischemia and cell damage à Formation and subsequent embolism.

CORONARY ARTERY DISEASE (continued)

Assessment Findings

a. Angina pectoris - most characteristic symptom

- mild to severe burning or squeezing retrosternal pain à may radiate to arm, jaw, neck, shoulder

- Relieved by rest and nitrates

b. Nausea and vomiting e. Cool, clammy skin

c. Dizziness and syncope f. Apprehension or a sense of impending doom

d. Diaphoresis

Laboratory and diagnostic study findings à ECG may appear normal when client is pain free

- ECG = ischemic changes (e.g. ST depression, T-wave inversion) during angina or exercise.

Nursing Management

> Administer prescribed meds – nitrates, antiplatelets, anticoagulants, antilipidemic, ß-blockers, CCB

> Provide care during acute anginal attack

1. Instruct client to stop all activities

2. Place px in a comfortable position

3. Place an NTG tablet under the tongue; wait for 5 minutes

> Request a STAT 12-lead ECG.

Support/reassure client and significant others during attack

> Promote Pain Relief - Encourage the client to reduce activity to a point at which pain does not occur

Prepare client for possible treatment

Drugs:

1. Nitrates - Nitroglycerin

2. Antiplatelets

a. Aspirin (ASA) - 160 or 325 mg tab p.o. given to pxs with angina

- prevents platelet activation

- reduces incidence of MI and death from CAD

- side effects: a. GI upset b. GI bleeding

b. Antiplatelets - Clopidogrel (Plavix), Ticlopidine (Ticlid)

- Given to patients who are allergic to ASA

- Effects seen after a few days

- Side effects: a. GI upset b. decreased neutrophil count

3. Anticoagulants

a. Unfractionated Heparin - may be given as IV bolus q 4 to 6 h and given as continuous infusion

- prevents formation of new blood clots

- amount based on results of aPTT

- heparin therapy considered therapeutic when aPTT is 1.5 to 2 times the normal aPTT value

b. Low-Molecular-Weight Heparin (LMWH) or Enoxaparin (Lovenox) or Dalteparin (Fragmin) – given SQ

- provides more effective and stable anticoagulation

- no need to monitor aPTT results

Both unfractionated heparin and LMWH increase the risk of bleeding

- antidote for Heparin: Protamine Sulfate

c. Warfarin (Coumadin) - Suppresses formation of prothrombin from vit. K

- Monitor for PT

- Warfarin therapy is considered therapeutic if INR is between 2.0 to 3.0

- Known to be affected by many medications

- Antidote: Vitamin K

4. Antilipidemics

a. Bile Acid Sequestrants – Cholestyramine (Questran), Colestipol, Niacin (Vit. B3 or Nicotinic Acid)

b. Fibric Acid Derivatives (Fibrates) – Gemfibrozil, Clofibrate

c. Statins – Atorvastatin (Lipitor), Simvastatin

5. Beta-blockers – antihypertensives – e.g. Metoprolol (Neobloc), Atenolol, Propranolol (Inderal)

6. Calcium Channel Blockers – (NeVaDA) – Nifedipine, Verapamil, Diltiazem, Amlodipine

Bleeding Precautions for pxs in Anticoagulant therapy

a. Apply pressure to the site of any needle puncture for a longer time than usual

b. Avoid IM injections

c. Avoid tissue injury and bruising from trauma

d. Avoid use of constrictive devices – e.g. continuous use of automatic BP cuff

e. Instruct px to use soft-bristled toothbrush

f. Teach px to use electric razor when shaving

g. Educate px to recognize signs of hemorrhage – e.g. hematuria, bleeding gums

h. Examine stool for occult blood

NOTES ON ECG/EKG

NON-INVASIVE

1. Electrocardiogram - graphic record produced by electrocardiograph

2. Electrocardiograph - a device used for recording the electrical activity of the myocardium by placing leads to certain points in the chest region

3. Electrocardiography - study of records of electric activity generated by the heart muscle

Placement of the Six (6) Electrodes

> V1 = 4th right intercostal space right parasternal border

> V2 = 4th left intercostal space left parasternal border

> V3 = halfway between V2 and V4

> V4 = 5th left intercostal space midclavicular line

> V5 = left anterior axillary line halfway between V4 and V6

> V6 = midaxillary line level with V4

Placement of Four (4) Lead Wires

> Lead 1 = RA right arm > Lead 3 = RL right leg

> Lead 2 = LA left arm > Lead 4 = LL left leg

6 CHEST LEADS –

V1 – V4 = anterior wall

V5 – V6 = lateral wall

Treatment Modalities used in CAD:

a. Percutaneous Transluminal Coronary Angioplasty (PTCA)

- It is a catheter-based therapy which is performed to relieve obstruction

- compressing blockage (atheroma) into intimal artery lining à ↑blood flow through the artery

- inserting an intravascular stent over the balloon during a PTCA

b. Coronary Artery Bypass Grafting (CABG)

- uses a blood vessel from the body to bypass occluded vessel à ↑blood flow through myocardium

- MEDIAN STERNOTOMY - Incision made in the sternum.

- Provides access for cardiac bypass & other procedures.

- Heart and vessels are altered to improve functioning

- Heart should be in cardioplegia

- Vena cavae & ascending aorta are cannulated & connected to tubings of a heart-lung machine.

- Commonly used replacements: femoral artery & vein; saphenous vein

- TYPES OF CANNULA used in CABG

a. Venous cannula: straight ended with multiple holes

b. Aortic cannula: angled tip, blood is directed towards the descending aorta

Nursing Management (continued)

> Provide teaching for the client and family

> Encourage: client à cardiac rehab program

Significant other/s à support group

> Provide teaching for the client and family

> Encourage family members and significant others to take a CPR course

MYOCARDIAL INFARCTION

- Reduced coronary blood flow à Deprivation of adequate blood supply to the myocardium à Destruction of myocardial tissue

- Effects of infarction - dependent on location and extent

- MI incidence: Men > Women

- Etiology

a. Atherosclerosis à narrowing of coronary artery à coronary artery spasm/complete arterial occlusion (embolism or thrombus)

b. hemorrhage or shock à ↓blood flow à profound imbalance b/n myocardial O₂ supply & demand.

c. Ischemia à depress cardiac function à trigger autonomic nervous system responses à ↑imbalance b/n myocardial O₂ supply and demand.

d. Persistent ischemia à tissue necrosis/scar tissue formation à permanent loss of myocardial contractility in the affected area

e. ↓Myocardial contractility, ↓pumping capacity à inadequate CO àCardiogenic shock

f. Ischemic myocardium is electrically unstable

> arrythmias include lethal ventricular fibrillation and ventricular tachycardia

> infarcts which interfere with the cardiac conduction system may lead to heart block or conduction defects

- Assessment Findings

1. Chest pain - persistent & crushing pain located substernally that radiates to arm, neck, jaw, or back

- unrelieved by rest or nitrates; silent MI may produce no pain

2. Nausea and vomiting

3. Dyspnea with or without crackles

4. Palpitations or syncope

5. Restlessness and anxiety or feeling of impending doom

6. Tachycardia or bradycardia

7. Decreased blood pressure

8. Altered S3 heart sounds – may indicate left ventricular failure

9. Oliguria

10. Levine’s sign

Laboratory and diagnostic findings

> ECG – > T-wave inversion or ST elevation or abnormal Q wave (old infarct)

> Serum enzyme studies: ↑Troponin I & T, CPK and CPK-MB, AST, LDH (flipped LDH pattern), Myoglobin

> Elevated WBC count – leads to elevated temperature

> Elevated ESR

Nursing Management

1. Administer Drug Therapy

2. Administer prescribed meds

- Morphine - Nitrates

- Antilipidemics - Thrombolytics

- Anticoagulants in acute situation - Stool softeners during rehabilitation

3. Administer Drug Therapy – in sequence! - Remember MONA!

- Morphine Oxygen = 2-4 L/min Nitroglycerin Aspirin

Morphine Sulfate (Duramorph, Astramorph) - given IV; serves as both analgesic & anxiolytic

- MOA: Reduces preload thus decreasing workload of the heart

- Side effects: a. hypotension b. respiratory depression

Thrombolytics – given IV

- Dissolves and lyses thrombus in the coronary artery

- Not used if px has a bleeding disorder

- Not given to patients with unstable angina

- Antidote: Aminocaproic Acid

- examples:

a. Streptokinase (Kabikinase, Streptase)

b. Tissue plasminogen activator (t-PA) - Alteplase (Activase)

c. Reteplase (r-PA, TNKase)

Nursing Management of MI (Continued)

4. Prepare the client for treatment such as PTCA and CABG

5. Provide client and Family teaching.

a. Encourage family members and significant others to take a CPR course.

b. Guidelines for the client with CAD are provided in client and family teaching.

6. Provide ongoing assessment.

a. Monitor cardiac enzymes

b. Monitor hemodynamic parameters as necessary through the multilumen pulmonary artery catheter

7. Minimize anxiety

8. Minimize metabolic demands.

> Institute a liquid diet

> advance to a low-sodium, low-cholesterol, low-fat, solid diet as tolerated

9. Encourage patient to participate in cardiac rehabilitation program

*Phases of Cardiac Rehab

Phase I = starts as px is admitted for ACS; consists of low-level activities

- initial education for px & family

a. s/sx that indicate the need to be brought to the ER c. rest-activity balance

b. medication regimen d. follow-up appointments with MD

Phase II = starts after px is discharged

= usually lasts for 4 to 6 weeks but may extend up to 6 months

- consists of supervised (often ECG-monitored) individualized exercise training

- education related to lifestyle modification

Phase III = focuses on maintaining cardiovascular stability and long-term conditioning (px is self-directed)

THREE THINGS TEACHERS WISH STUDENTS KNEW

2009-11-11T06:11:00.000-08:00

June 03, 2007

Queena Lee-Chua

Inquirer

MANILA, Philippine - When I ask my students: "How can you make the most of school?" they dutifully recite stock answers: Study hard. Come to school prepared. Do not cram. Avoid cheating. Better behave in class, or else.

I agree with everything, except the last one. I would rather have a class of lively students who challenge everyone with insights, rather than a group of silent automatons who regurgitate everything I say.

That said, my students have missed important points. Study hard, yes, but study wisely, too. Come to school prepared, not just with materials, but also with SMART goals. Do not cram, so make sure to master the basics beforehand. Avoid cheating, certainly, but outside of exams, never be afraid to ask for help.

Set SMART goals

Companies expend a lot of effort on five- or 10-year plans. Bankers help us save for retirement. Learners also need to set goals— SMART goals.

A goal is Specific. What do you want to accomplish? Instead of saying: "I want to be a good student," which is vague, state the goal clearly: "I want to get an average of 90 percent in History by the end of the quarter."

A goal is Measurable. You need to keep track of your progress. For example, "So far, I have received good scores on three quizzes. I need to practice my oral presentation, so I can maintain my average."

A goal is Action-Oriented. Merely dreaming about a good grade is not enough. You need to take action to achieve your goal. "To do well in History, I need to do my assignments and read the textbook regularly."

A goal is Realistic. Decide if a goal is attainable in the first place, and then think about how much effort, time and resources you can expend to reach your goal.

When I was a freshman in college, my goal was to learn as much math and English as I could, and do my best in other subjects. However, advanced placement classes meant solving math problems and writing compositions every day, on top of homework and term papers in other subjects. I was a class officer and a member of the Math Club, with frequent meetings and activities. To top it off, I yearned to be part of the swim team, which entailed frequent lengthy practice sessions.

I managed time pretty well, but there was no way I could do everything. Something had to give. I did not want to lose sight of my goal, which, after all, was mainly academic. There was no way I could sacrifice my studies. So with great reluctance, I dropped the swim team. In this lifetime, I would never be Christine Jacobs, but I could be a mathematician.

A goal is Time-Bound. How much have you achieved at a certain point? "If I want a good grade in History at the end of the quarter, which is a month away, do I focus more on the textbook, or do I revise my term paper? If both, how much time do I spend on each task?"

Ask for help

Seek help at the first sign of trouble. Students dread report card time, but I will tell you a secret: so do teachers. Parents, tutors and the rest of the extended family descend en masse to threaten or plead with teachers to "reconsider" failing marks. By then, it is too late.

When we fall ill, we go to the doctor at once. When we are hungry, we look for something to eat. Why then do students delay seeking help when they don't understand a lesson?

On the first day of class, I tell my students: "When you do not understand something, please seek help at once. Turn to a classmate, do research in the library or on the Net, ask your parents or consult me. If you let the little problems pile up, then you will be over whelmed later on."

In a class of 40 students, it is impossible for teachers to meet the learning needs of everyone. One-on-one tutorials may be essential for slower or faster learners. I inform students of my regular consultation hours, and I am happy that many of them use this opportunity to enhance learning. For students who need to brush up on the basics, I go through exercises with them in detail. For those who prefer a challenge, I discuss advanced topics or pose more complex problems.

Teachers, good teachers, at least, welcome questions. Last year, when my son was in Grade 2, his Science teacher told me: "I like the fact that Scott is not afraid to ask questions if he wants to clarify things. I especially admire him for doing the asking himself. Mostly, parents are the ones who call me up, and sometimes I wonder if they or their sons are the ones with the questions. I hope they are not doing the homework for their kids."

When the teacher discusses a lesson, review the details later in the day, even if the test is still far away. If a point is not clear, reflect on it for a while. If you really cannot understand it, then seek help as soon as possible. Do not close your eyes and pray that you will never see the topic again. According to Murphy's Law, the topics you don't know are most likely the ones you will meet in the test.

Master the basics

My friend was frantic. "Can you help my daughter? She does not know division and she has a test next week. I have been sitting beside her for four hours, and we have not made progress. Now I am yelling at her, and she is crying. I don't know what to do."

Sure enough, her daughter, whom I will call Riza, could not do division. But what my friend neglected to mention was that Riza could barely do multiplication either. Four hours, even four times four hours, of hard work was not the best strategy here. If Riza did not know that 4 times 6 is 24, then how could she tackle 24 divided by 4?

Rizas problem was not so much division itself, but lack of mastery of the skills required for division. I was not surprised to learn that Riza had also flunked a previous test for multiplication.

"Can't we just do division now, and go back to multiplication next time," she pleaded, "since the coming test will be on division anyway?"

Sorry, no way. New knowledge builds on prior learning and, for a subject like math, where one concept leads to another, mastery of the basics is essential. For the next four days, we did nothing but multiplication. I introduced songs, pointed out number patterns and advised Riza to eat memory-boosting foods.

We studied division only during the last two days, but by then, spurred by freshly learned multiplication facts and a giant fear of failure, Riza was able to grasp the concepts. She got 80 percent on the test, and would have gotten higher if she had finished the 50 items.Of course, to totally master a topic, how could a week, however intensive it had been, ever be enough?

Once, when I asked a student why he failed a test, he admitted: "I did not understand Chapter Two, so I skipped the pages and went to Chapter Three. But I got lost. I was hoping to catch up in the next chapter, but things got worse."

Studying hard is important, but it is also essential to study wisely. If you cannot comprehend a complex topic, chances are you have not understood the concepts leading up to it. Instead of banging your head on the proverbial wall, or worse, giving up, why don't you go back to earlier lessons? Again, seek help if needed.

Learning is not easy, but then, things worth doing seldom are. But with the right mindset, proper support and good habits, learning can not only be endured, but even enjoyed as well. Have a great school year!

Queena N. Lee-Chua is a professor of mathematics and psychology at the Ateneo de Manila University.

Antibiotics

2009-11-11T06:07:00.000-08:00

Antibiotics

An antibiotic is a chemical compound that inhibits or abolishes the growth of microorganisms, such as bacteria, fungi, or protozoans. The original meaning of antibiotic includes any agent with biological activity against living organisms; however, the term is commonly used to refer to substances with anti-bacterial, anti-fungal, or anti-parasitical activity. The first antibiotic compounds used in modern medicine were produced and isolated from living organisms, for example, the penicillin class produced by fungi in the genus Penicillium, or streptomycin from bacteria of the genus Streptomyces. With the advent of organic chemistry many antibiotics are now also obtained by chemical synthesis, such as the sulfa drugs. Many antibiotics are relatively small molecules with a molecular weight less than 2000 Da.

Unlike previous treatments for infections, which often consisted of administering chemical compounds, such as strychnine and arsenic with high toxicity also against mammals, antibiotics from microbes had no or few side effects and high effective target activity. Most anti-bacterial antibiotics do not have activity against viruses, fungi, or other microbes. Anti-bacterial antibiotics can be categorized based on their target specificity: "narrow-spectrum" antibiotics target particular types of bacteria, such as Gram-negative or Gram-positive bacteria, while broad-spectrum antibiotics affect a wide range of bacteria.

The effectiveness of individual antibiotics varies with the location of the infection, the ability of the antibiotic to reach the site of infection, and the ability of the microbe to inactivate or excrete the antibiotic. Some anti-bacterial antibiotics destroy bacteria (bactericidal), whereas others prevent bacteria from multiplying (bacteriostatic).

Oral antibiotics are simply ingested, while intravenous antibiotics are used in more serious cases, such as deep-seated systemic infections. Antibiotics may also sometimes be administered topically, as with eye drops or ointments.

Classes of antibiotics

At the highest level, antibiotics can be classified as either bactericidal or bacteriostatic. Bactericidals kill bacteria directly where bacteriostatics prevent them from dividing. However, these classifications are based on laboratory behavior; in practice, both of these are capable of ending a bacterial infection.

Production

Since the first pioneering efforts of Florey and Chain in 1939, the importance of antibiotics to medicine has led to much research into discovering and producing them. The process of production usually involves screening of wide ranges of microorganisms, testing and modification. Production is carried out using fermentation; a process that is important in anaerobic conditions when there is no oxidative phosphorylation to maintain the production of adenosine triphosphate (ATP) by glycolysis.

Side effects

Possible side effects are varied, depend on the antibiotics used and the microbial organisms targeted. Adverse effects can range from fever and nausea to major allergic reactions including photodermatitis. One of the more common side effects is diarrhea, sometimes caused by the anaerobic bacterium Clostridium difficile, which results from the antibiotic disrupting the normal balance of the intestinal flora, which may be alleviated by ingesting probiotics) . An antibiotic-induced disruption of the population of the bacteria normally present in the healthy vagina (=constituents of the normal vaginal flora) may also occur. Other side effects can result from interaction with other drugs, such as elevated risk of tendon damage from administration of a quinolone antibiotic with a systemic corticosteroid.

It is a common assertion that some antibiotics can interfere with the efficiency of birth control pills. Although there remain few known cases of complication, the majority of antibiotics do not interfere with contraception, despite widespread misinformation to the contrary.

Antibiotic misuse

Common forms of antibiotic misuse include failure to take the entire prescribed course of the antibiotic, or failure to rest for sufficient recovery allowing clearance from the infecting organism. These practices may cause the development of bacterial populations with antibiotic resistance. Inappropriate antibiotic treatment is another common form of antibiotic misuse. A common example is the use of antibacterial antibiotics to treat viral infections such as the common cold.

It is estimated that greater than 50% of the antibiotics used in U.S. are given to feed animals (e.g. chickens, pigs and cattle) in the absence of disease. Antibiotic use in food animal production has been associated with the emergence of antibiotic-resistant strains of bacteria including Salmonella spp., Campylobacter spp., Escherichia coli, and Enterococcus spp. Excessive use of prophylactic antibiotics in travelers may also be classified as misuse.

Antibiotic resistance

Use or misuse of antibiotics may result in the development of antibiotic resistance by the infecting organisms, similar to the development of pesticide resistance in insects. Evolutionary theory of genetic selection requires that as close as possible to 100% of the infecting organisms be killed off to avoid selection of resistance; if a small subset of the population survives the treatment and is allowed to multiply, the average susceptibility of this new population to the compound will be much less than that of the original population, since they have descended from those few organisms which survived the original treatment. This survival often results from an inheritable resistance to the compound which was infrequent in the original population but is now much more frequent in the descendants thus selected entirely from those originally infrequent resistant organisms.

Antibiotic resistance has become a serious problem in both the developed and underdeveloped nations. By 1984 half of the people with active tuberculosis in the United States had a strain that resisted at least one antibiotic. In certain settings, such as hospitals and some child-care locations, the rate of antibiotic resistance is so high that the normal, low cost antibiotics are virtually useless for treatment of frequently seen infections. This leads to more frequent use of newer and more expensive compounds, which in turn leads inexorably to the rise of resistance to those drugs, and a race to discover new and different antibiotics ensues, just to keep us from losing ground in the battle against infection. The fear is that we will eventually fail to keep up in this race, and the time when people did not fear life-threatening bacterial infections will be just a memory of a golden era.

Another example of selection is Staphylococcus aureus, which could be treated successfully with penicillin in the 1940s and 1950s. At present, nearly all strains are resistant to penicillin, and many are resistant to nafcillin, leaving only a narrow selection of drugs such as vancomycin useful for treatment. The situation is worsened by the fact that genes coding for antibiotic resistance can be transferred between bacteria via plasmids, making it possible for bacteria never exposed to an antibiotic to acquire resistance from those which have. The problem of antibiotic resistance is worsened when antibiotics are used to treat disorders in which they have no efficacy, such as the common cold or other viral complaints, and when they are used widely as prophylaxis rather than treatment (as in, for example, animal feeds), because this exposes more bacteria to selection for resistance.

Nitrate in Drinking Water

2009-11-11T06:01:00.000-08:00

Guide M-114

Craig Runyan, Extension Water Quality Specialist

College of Agriculture and Home Economics New Mexico State University

This Publication is scheduled to be updated and reissued 9/02.

Nitrate (NO3) is the primary source of nitrogen (N) for plants; it is a nutrient they cannot live without. Nitrates occur naturally in soil and water. Extensive farming can rob the soil of its natural nitrogen source, so farmers often add nitrate fertilizers. Properly managed, nitrogen does not endanger health and can increase crop production. However, when more nitrogen is added to the soil than plants can use, excess nitrate can leach into groundwater supplies and contaminate wells. On-site sewage systems (such as septic tanks and lagoons) also can be a source of nitrate pollution. Because nitrate is converted to a very toxic substance (nitrite) in the digestive systems of human infants and some livestock, nitrate-contaminated water is a serious problem.

How does nitrate affect families?

Human babies are extremely susceptible to acute nitrate poisoning because of certain bacteria that may live in their digestive system during the first few months of life. These bacteria change nitrate into toxic nitrite (NO2). The nitrite reacts with hemoglobin (which carries oxygen to all parts of the body) to form methemoglobin, which does not carry oxygen. The level of oxygen being carried throughout the body decreases in proportion to the amount of hemoglobin converted to methemoglobin. As the oxygen level decreases, the baby is suffocated. This condition is called methemoglobinemia.
The most obvious symptom of nitrate poisoning is a bluish color of the skin, particularly around the eyes and mouth. This is called cyanosis. A baby with these symptoms should be taken to an emergency medical facility immediately. The doctor will take a blood sample to be sure the baby is not suffering from nitrate poisoning. The blood sample of an affected baby is a chocolate brown instead of a healthy red. Nitrate poisoning can be treated, and in most cases the baby makes a full recovery. It is crucial, however, to deal with the problem immediately, because without treatment a baby can die.
Around the age of three months, an increase in the amount of hydrochloric acid in a baby's stomach kills most of the bacteria that convert nitrate to nitrite. By the time a baby is six months old, its digestive systems should be fully developed, and none of the nitrate-converting bacteria remain. However, children under one year of age and pregnant women are at risk for adverse effects. In older children and adults, nitrate is absorbed and excreted, and methemoglobinemia is no longer a concern.

How does nitrate affect livestock?

Ruminant animals (such as cows and sheep) and infant monogastrics ( such as baby pigs and chickens) also have nitrate-converting bacteria in their digestive systems. For this reason, nitrate poisoning affects them the same way it affects human babies. Because adult monogastrics generally do not have nitrate-converting bacteria, they are not affected by methemoglobinemia. Horses, however, are an exception. They are monogastric, but they also have a cecum, which is similar to a rumen. The nitrate-converting bacteria living in the cecum increase the risk of nitrate poisoning.
Livestock are exposed to nitrate in feed as well as in water. Crops harvested after weather stress (such as drought) are especially likely to have high nitrate contents. To protect livestock, fodder can be tested for nitrate before being fed. The symptoms of nitrate poisoning in animals include a bluish or brownish discoloring of nonpigmented areas (around the mouth and eyes) or mucous membranes, a sluggish, staggering gait, rapid heartbeat, frequent urination and labored breathing followed by collapse. In severe cases, convulsion and coma may occur, followed by death one to three hours after the first signs appear.
A veterinarian should be contacted as soon as any of these symptoms are noticed. Blood for diagnosis must be drawn while the animal is alive or within two hours after death. Blood from affected animals will have a chocolate brown color. If the problem is diagnosed in time, animals can be treated and often fully recover. Pregnant animals that recover may abort within a few days.

How much nitrate is dangerous?

The federal government has set drinking water quality standards to offer the greatest protection to infants. The standard of ten milligrams per liter (mg/l) nitrate-nitrogen has a small margin of safety built into it. Because of this safety factor, some individuals can drink water exceeding the standard and show no adverse affects. However, levels above this standard are considered potentially hazardous.
Currently, there is no regulatory drinking water quality standard for livestock. Researchers suggest a level of 100 mg/l of nitrate-nitrogen. Strong animals may tolerate higher levels, but this level is designed to protect animals that are unhealthy, very young, pregnant or on a low-energy diet. Nitrate levels in feed and forage must also be considered in rations for ruminant animals. For more information see NMSU Extension Guide M-112, "Water Quality for Livestock and Poultry."

How does nitrate get into the water?

Nitrate contamination occurs when there is more nitrate in the soil than plants can use and when water can move easily through the soil and underlying rock. The excess nitrate is carried through the soil into groundwater supplies by irrigation, rainwater, and snowmelt. This occurs particularly where the soil is sandy, gravely, or shallow over porous limestone bedrock. Excess nitrate can accumulate in the soil in several ways.
First, manure and septic system effluent contain both ammonia and organic forms of nitrogen. Organic nitrogen may be converted to ammonia in the soil. This ammonia, along with any ammonia fertilizer that is applied, is converted to nitrate by soil bacteria in a process called nitrification. Nitrification is important because plants can only use nitrogen in the nitrate form. However, when more ammonia is nitrified than plants can use, the unused nitrate will accumulate in the soil.
Second, applying more nitrate fertilizer to the soil than a crop can use will build up high levels of nitrate. Finally, legume plants, such as alfalfa, can take nitrogen out of the air and put it into the ground through their root nodules. This process is called nitrogen fixation. Small amounts of nitrate also enter the soil with rain during electrical storms. Neither process produces contaminating amounts of nitrate on its own, but both should be taken into consideration when determining how much fertilizer is needed.

How to tell if water is contaminated with nitrate

Because nitrate is colorless, tasteless, and odorless, water must be chemically tested to determine if it is contaminated. Many laboratories in New Mexico will test private water supplies for nitrate. To have your water tested, you must get a sample container from the laboratory, draw the sample as directed by the lab and get the sample to the lab as quickly as possible to ensure a reliable test. For information on testing labs in your area, contact your local county Extension office or local health department.
Accurately determining the nitrate level in a well can be difficult because nitrate levels vary according to the time of year. For this reason, the best time to test is during periods of irrigation, high rain fall, or snowmelt when leaching of excess nitrate into the groundwater is most likely to occur. A water test done in late fall can be misleading because the well may be temporarily low in nitrate if there have been no heavy rains.
To protect the health of your family and livestock, annual water tests should also be made for bacteria, total dissolved solids, and pH.
If your well has been tested and the report shows that the water is contaminated with high nitrate levels, you must immediately stop feeding it to infants. As alternatives to contaminated water, you can plan to breast feed, feed formula prepared with bottled water, or feed pre-mixed infant formula.

How can nitrates be reduced or removed from water?

Nitrate is a very soluble substance, easily dissolved in water and extremely hard to remove. Treatment for nitrate is, therefore, very complicated and expensive. The three methods of reducing or removing nitrate are:

demineralization by distillation or reverse osmosis
ion exchange
blending

Demineralization removes nitrate and all other minerals from the water. Distillation is one of the oldest, most effective types of demineralization. The distilling process has only three steps:

the water is boiled;
the resulting steam is caught; and
the steam is condensed on a cold surface, turning back into water.

The nitrate and other minerals remain concentrated in the boiling tank.
Reverse osmosis is another way to demineralize water. It reduces but does not remove all nitrates. In a reverse osmosis system, the water is put under pressure and forced through a membrane that filters out minerals and nitrate. One-half to two-thirds of the water remains behind the membrane as rejected water. The yield of treated water to reject water is related to the amount of pressure applied; the lower the water pressure, the greater the volume of reject water. Higher-yield systems use water pressures in excess of 150 psi. The systems that operate using standard household water pressure (35 to 45 psi) will yield some treated water, but a large amount of untreated water goes down the drain, and could reduce the efficiency of home septic systems. Household units are usually small enough to fit under the sink or on a kitchen counter.
Both of these demineralization systems require a lot of energy to operate efficiently and are high-maintenance systems. They are also low-yield systems that may provide enough water for a family, but cannot produce the large quantities needed for livestock.
The second type of water treatment for nitrate contamination is ion exchange. Ion exchange introduces another substance that trades places with the nitrate. Most often chloride is exchanged for nitrate. The ion exchange unit is a tank filled with special resin beads that are charged with chloride. As water containing nitrate flows through the tank, the resin takes up nitrate in exchange for chloride. In time, all the chloride will be exchanged for nitrate. The resin can then be recharged by back washing with a brine solution (sodium chloride) and reused.
Because ion exchange systems can treat large volumes of water, they are more appropriate than demineralization for treatment of livestock water supplies. There are, however, some drawbacks to ion exchange systems. First, in addition to exchanging nitrate, the resin beads will also take up sulfate in exchange for chloride. Therefore, if sulfates are present in the water supply, the capacity of the resin to take up nitrate is reduced. Second, the resin may also make the water corrosive. For this reason, the water must go through a neutralizing system after going through the ion exchange unit. Finally, backwash brines, which are high in nitrate, must be disposed of properly so they do not re-contaminate the groundwater supply.
The third and most common way to reduce nitrates is to dilute the nitrate-polluted water by blending it with water from another source that has low nitrate concentrations. Blending the two waters produces water that is low in nitrate concentration. Blended water is not safe for infants but is frequently used for livestock.
There is no simple way to remove all nitrate from your water. Although it is common to think of boiling, softening or filtration as a means of purifying water, none of these methods reduce nitrate contamination. Boiling water is, in fact, the worst thing to do because it actually concentrates the nitrate. Softening and filtration do nothing at all to remove nitrate.

How can a water supply be protected from nitrate contamination?

When selecting a new well location, be sure to consider possible sources of contamination. Generally, the farther water travels through soil, the safer it becomes as contaminants are diluted or filtered out. Nitrate is an exception. It is not filtered out of water by the soil, so a new well must be totally isolated from nitrate leaching to prevent contamination. Because different soils have different filtering abilities, standards for well depths and for distances between wells and contaminants cannot guarantee a safe well. The minimum standards governing on-site sewage systems specified by the New Mexico Environment Department are intended to provide the minimum distances and standards to protect private groundwater and surface water supplies.
New and existing wells also need to be protected from surface drainage. Barnyard surface runoff, for example, can drain directly into an unprotected well and cause serious contamination. Also, if a well is not properly cased, subsurface drainage can move down beside the well casing and contaminate groundwater. Abandoned wells must also be properly sealed to prevent similar groundwater contamination. For more information on well placement and protection, contact the New Mexico Environment Department or local Cooperative Extension office. You may also want to request the Extension publication, New Mexico Farm*A*Syst, Farmstead Assessment System from NMSU Agricultural Communications, Box 30003, MSC 3AI, Las Cruces, NM 88003, or call (505) 646-3228.

How can nitrogen be managed?

Since nitrate leaches through the soil into the groundwater, the only way to ensure a safe water supply is to control the application of nitrogen to the surface of the ground. The key to good nitrogen management is to match the nitrogen application to the needs of the crop.
Farmers should not overlook the nutrient value of their livestock manure. Manure has significant nutrient value and should be considered and subtracted from calculations of fertilizer needs. Manure can reduce fertilizer costs and still provide enough nitrogen for crops, while leaving little nitrate to leach down into the groundwater.
Manure application practices also can affect the leaching of nitrate into the groundwater. For instance, if the manure is applied sooner than the crop can use it, a large portion of the nitrate can be lost by leaching.
To save manure for the best application time, a well-engineered, well-constructed storage unit should be provided. The storage units must be large enough to contain the manure without overflowing and must be properly lined to prevent seepage to the ground-water. Manure management systems for large operation are regulated by state and federal environmental agencies. For smaller operations, consult the New Mexico Farm*A*Syst publication or your local Extension agent.

"We've been using this water for years and we're OK."

Water can have nitrate levels that are above the EPA standard and still have no obvious effect on your family. This is not surprising for a number of reasons.

Methemoglobinemia only affects infants, young monogastrics, and ruminant animals.
To protect infants, the water quality standard has a small margin of safety.
The symptoms of nitrate poisoning might be confused with those of respiratory problems or illness such as congenital heart disease. A blood test is needed to confirm the condition.
Because of the fluctuations in the levels of nitrate from year to year, a safe water supply may become unsafe.

Remember that nitrates are essential nutrients for plant growth. Only when there is too much nitrate in the soil does it become a problem in water. Routine water testing is important to protect the health of both families and animals. If nitrate levels in a water supply exceed the low-nitrate water must be provided for infants to drink. Nitrogen management, the only long-term solution to nitrate contamination, requires consideration of all aspects of nitrogen sources. The problem of nitrate contamination is not a simple one, but it must be faced to protect families, animals, and the environment.

Two ways of reporting nitrate concentrations: Know the difference!

When your report on the water test comes back from the lab, the nitrate concentration can be reported either as nitrate (NO3) or as nitrate-nitrogen (NO3-N). Be sure you know which reporting system is being used because the acceptable concentrations of each are considerably different. If the lab reports its results as nitrate, the drinking water quality standard is 45 mg/l. If the lab reports its results as nitrate-nitrogen, the drinking water quality standard is 10 mg/l. A milligram per liter (mg/l) is also equal to one part per million (ppm). If you are unsure of how to interpret the report, contact the lab, your local Extension office, or local health department. It is important to check the lab report carefully because the two systems are frequently interchanged.

Glossary

Cyanosis. A blue color of the skin caused by lack of oxygen.
Demineralization. The removal of all minerals from water.
Inorganic nitrogen. Nitrogen in the form of ammonia and nitrate; available commercially as ammonia gas, urea, and ammonium-nitrate fertilizer.
Leaching. The movement of materials (such as nitrate) down throughthe soil with water.
Methemoglobin. Formed by nitrate combined with hemoglobin in the blood; does not carry oxygen to body cells.
Methemoglobinemia. The presence of methemoglobin in the blood; can be caused by nitrate poisoning; commonly called blue-baby disease.
Monogastrics. Animals with only one stomach, such as pigs, horses, and chickens.
Nitrification. The conversion of ammonia to nitrate by bacteria in the soil.
Organic nitrogen. The nitrogen obtained from plant and animal material, such as manure or crop residue.
Resin. An artificial plastic material used in ion exchange systems such as water softeners and nitrate filters.
Ruminants. Animals that have a rumen in their digestive system; the bacteria in a rumen convert nitrate to nitrite.
Water quality standard. The level of pollutants considered by law to be safe. Standards apply to and are enforced for public water supplies.

STRESS - A Common Med Problem

2009-11-11T05:58:00.000-08:00

"EU- stress"

"DIS-stress"

Levels of stress

1. Immediate

2. Delayed

3. Chronic

Psychosis

· Loss of reality testing

o Loss of interest

· Impairment of mental functioing

· Delusions

o False, fixed belief

· Hallucinations

o May occur in any sensory modality—visual, auditory, olfactory, gustatory, tactile, proprioceptive, equilibrioceptive, nociceptive, thermoceptive.

· Confusion

· Impaired memory

· Severe impairment of social and personal functioning

· Inability to perform the usual household or occupational roles

Neurotic

· Chronic or recurrent non-psychotic disorder characterized mainly by anxiety

· Has a sense of reality

Symptoms

· Obsession

· Compulsion

· Phobia

· Sexual dsfunction

· Recognized by the individual as unaceptable and alien

· Does not actively ciolate gross social norms (but disabling )

· Enduring or recurrent if not treated

· Not limited to a transitory reaction to stressors

· Broad range of signs and symptoms

Middle Age - Psychiatry Transcription

2009-11-11T05:52:00.000-08:00

MIDDLE AGE:

VOCATIONAL AND FAMILY ADJUSTMENTS

Centers around work and family
Has greater effect on women

VOCATIONAL ADJUSTMENT (thrown out of work to give way to young adults)

Sex differences in vocational adjustment

Men reach vocational success in status and income.

When unsatisfied

Tends to change job
Line of work
Vocational instability

Ending of responsibility for the support of the children.
Realization of declining opportunity to change job.

Women has lesser chance of being hired, increased salary and promoted than men

True in all except “women fields”.

Elementary school teaching, nursing, beauty culture and other similar jobs.

Less desire to stay in the same job and tends to career.

Assessment of vocational adjustment

Achievement

Success in terms of

Income
Prestige
Authority
Autonomy

Based on what he had hoped for during his younger days.
Women fail to achieve vocational success for those who stop working after marriage.

Satisfaction

Little chance for adjustment.
Nearing compulsory retirement.
Pressure of work due to aging.

CHANGED WORKING CONDITIONS THAT AFFECT MIDDLE-AGED WORKERS

Unfavorable social attitude

To old to learn new skills to keep pace with the young adults.
Uncooperative in their relations with coworkers.
Absenteeism due to failing health.

Hiring policies

Companies believed that maximum production can be achieved by hiring young workers.
More economical because of the high amount of retirement pension unlike the young adults.

Increased use of automation

For those who have low intelligence.
Training for specific lines of work only.
Health that causes them to work more slowly.

Group work

Training puts stress on their social adjustment.

Role of wife

As husband becomes successful; wife tends to become successful in his own field (community affair).

Compulsory retirement
Dominance of big business

Workers of small companies that had been merged to large ones feel that they have no place for them in the new organization.

Relocation

Moving to new location assigned to sustain the job (managerial)

CONDITIONS INFLUENCING VOCATIONAL ADJUSTMENTS IN MIDDLE-AGE

Satisfaction with work

For those who work for the family rather that the line of job they like

Opportunities for promotion
Vocational expectations

Assess their achievement in light of his earlier aspiration

Increased use of automation

Boredom and lack of pride in their work.
Possibility of losing job

Nervous
Unwillingness to retain

Attitude of spouse on:

Status
Low pay
Far from home

Attitude towards big business
Attitude toward coworkers

For those who resent the treatment they receive from their superiors or their coworkers

Relocation

CONDITION CONTRIBUTING TO VOCATIONAL SATISFACTION

Achievement of goal set earlier
Satisfaction of family members on the achievement
Opportunities for self actualization
Congenital relationship with coworkers
Satisfaction with the treatment from the management
Satisfaction with the provision given by the company
Security on the job
Relocation

ADJUSTMENT TO CHANGED FAMILY PATTERNS (withdrawal of children from the family and taking care of aging parents)

Women are more affected

· Physical and attitude changes due to aging and loss of reproductive function

Men can compensate changes by deriving added satisfaction from work

Marriage disenchantment

o Lack of vocational success

§ Strains of family life

§ Unfavorable attitudes of family members towards his work

o In women, they feel disenchanted when she;

§ Feels useless after her maternal responsibilities\

§ His husband is more consernd about work

Adjustment to changed roles

· “Empty nest” period

o When children leaves home

o Depends on the size of the family

§ Smaller has greater effect

§ Threat when the expected child is not successful

o Difficulties for those who hane/are:

§ Few outside interest (only to her children)

§ Overly protective and possessive parents

· Adjustment to spouse

o Dependent again upon each other for companionship

· Sexual adjustments

o Increased after “launching stage”

o Poor sexual adjustments are due to:

§ Difference of sex drives

§ Men is concerned with loss of sexual vigor

§ Women develop more interest in sex

§ Last chance to conceive

§ Little satisfaction from coitus

· Adjustment to in-laws

o Children’s spouse

o Taking care of aging parents

§ Conditions affecting adjustment

· Role reversal

· Place of residence

· Degree of responsibility

o If considered burden

· Relationship of aging parent to middle-aged person

o If parent or an in-law

· Role played by elderly parents

o If able to help to chores and not burden

· Sex of elderly parent

o Men cause less work and interfere less than women

· Earlier experiences with elderly parent

· Attitude toward elderly parents

Deprived of opportunities for new interests when both

· Adjustment to grand parenthood

o Roles played by grandparents

§ Formal role

· Hands of policy

§ Fun-seeking role (without responsibilities)

§ Surrogate-parent role

§ “Reservoir of family wisdom” role

§ Distant figure role

CONDITIONS COMPLICATING ADJUSTMENT TO CHANGED FAMILY PATTERNS IN MIDDLE-AGE

Physical changes

Menopause and climacteric

Loss of parental roles
Lack of preparation
Feeling of failure
Feeling of uselessness

When parental role diminished

Marriage disenchantment
Care of elderly relatives

ADJUSTMENT TO SINGLEHOOD (single, widowed, divorced)

Unmarried are adjusted to being single

Women are realistic that it is harder to have a spouse at forties
Men find it more advantageous to be a bachelor

Problem of single women are:

Employment and vocational advancement
Expected to take care of elderly parent

Financial, physical and emotional burden

A Good Example of Middle Age. My Parents On Their 40s. Celebrating Love and Life Together.

Family Life Cycle - Preventive Medicine

2009-11-11T05:49:00.001-08:00

Topic Overview

What is a family life cycle?

The emotional and intellectual stages you pass through from childhood to your retirement years as a member of a family are called the family life cycle. In each stage, you face challenges in your family life that cause you to develop or gain new skills. Developing these skills helps you work through the changes that nearly every family (traditional or nontraditional) goes through.

Not everyone passes through these stages smoothly. Situations such as severe illness, financial problems, or the death of a loved one can have an effect on how well you pass through the stages. Fortunately, if you miss skills in one stage, you can learn them in later stages.

The stages of the family life cycle are:

· Independence.

· Coupling or marriage.

· Parenting: Babies through adolescents.

· Launching adult children.

· Retirement or senior years.

Why is it important to understand the family life cycle?

Mastering the skills and milestones of each stage allows you to successfully move from one stage of development to the next. If you don't master the skills, you may still move on to the next phase of the cycle, but you are more likely to have difficulty with relationships and future transitions. Family life cycle theory suggests that successful transitioning may also help to prevent disease and emotional or stress-related disorders.

Whether you are a parent or child, brother or sister, bonded by blood or love, your experiences through the family life cycle will affect who you are and who you become. The more you understand about the challenges of each stage of the cycle, the more likely you are to successfully move on.

What can disrupt the normal cycle?

The stress of daily living or coping with a chronic medical condition or other crisis disrupts the normal family cycle. A crisis or ongoing stress can delay the transition to the next phase of life, or you may move on but without the necessary skills to succeed.

How can I improve my family life cycle?

Be assured, you can learn missed skills and improve your and your family's quality of life at any stage. Self-examination, education, and perhaps counseling are ways to improve yourself and your family life. These are also actions that can help you manage other issues such as going through a divorce or being a part of a nontraditional family structure.

Independence Stage

Independence is the most critical stage of the family life cycle. As you enter young adulthood, you begin to separate emotionally from your family. During this stage, you strive to become fully able to support yourself emotionally, physically, socially, and financially. You begin to develop unique qualities and characteristics that define your individual identity.

Intimacy is a vital skill to develop during your independent, young adult years. Intimacy is the ability to develop and maintain close relationships that can endure hard times and other challenges. In an intimate relationship, you learn about:

· Commitment.

· Commonality or similarity.

· Compatibility.

· Attachment.

· Dependence on another person who is not in your family.

· Shared emotion in a relationship.

You also learn who you are outside of your identity within your family. Your ability to develop an intimate relationship depends on how successful you were at developing your individual identity earlier in life.

Exploring interests and career goals is part of developing independence. To live successfully away from your family, you must develop financial and emotional independence.

You also begin to be responsible for your own health in this stage, becoming responsible for your nutritional, physical, and medical needs. Developing healthy habits at this time—such as good nutrition, regular exercise, and safe sex practices—is important for lifelong good health and happiness.

You learn new aspects of independence throughout your lifetime. Even when you have moved on to another stage of life, such as coupling, you continue to learn independence within the context of that stage.

During the independence stage, you hope to:

· Learn to see yourself as a separate person in relation to your original family—parents, siblings, and extended family members.

· Develop intimate peer relationships outside the family.

· Establish yourself in your work or career.

Other important qualities you develop during this phase include:

· Trust.

· Morals.

· Initiative.

· Guilt.

· Work ethic.

· Identity, or who you are in the world.

Coupling Stage

After you achieve independence, the next stage in the family life cycle is coupling. You explore your ability to commit to a new family and a new way of life. While being in a committed relationship with someone without the act of marriage does involve a process of adaptation and relationship building, marriage often requires unique skills.

When you join families through marriage, you form a new family system. Your family blueprint—your personal ideas, expectations, and values, shaped by the relationships and experiences with your original family—combines with your spouse's to form a new family blueprint. This requires reshaping your and your spouse's goals. In the most functional marriages, partners combine their beliefs and behaviors in a synergistic way. Synergy in the family life cycle is the ability to take two different points of view and create an option that neither person had considered. It differs from a compromise in that it is not giving up something; rather, it is using the energy from the two people to create a third, better option.

You may find that some of the ideas or expectations that you held in the past are not realistic at this stage. Some common areas of adjustment include:

· Finances.

· Lifestyle.

· Recreational activities or hobbies.

· Relationships with in-laws.

· Sexuality or sexual compatibility.

· Friendships.

· Putting another person's needs before your own.

The ultimate goal at this stage is to achieve interdependence, which occurs when you are able to fully enter into a relationship with another person. Interdependence also requires that you share goals and that you are able to occasionally place the needs of another above your own. However, before you can achieve interdependence, you must have first acquired a high degree of independence.

The relationship skills you learn in coupling serve as a foundation for other relationships, such as parent-child, teacher-student, or physician-patient.

Within a couple, you learn:

· Advanced interpersonal communication.

· Problem-solving skills.

· Common spiritual and emotional development goals.

· How to form boundaries in relationships.

· When to place the needs or importance of the other person above your own.

Most research indicates that early on, a happy marriage is full of passion and sexual intimacy, which can become less important in later successful marriage. A satisfying marriage at this stage includes a high amount of considerate or kind acts (such as doing something nice for the other person without being asked) and praise.

The life skills you learn in this stage are important in developing true interdependence and the ability to have a cooperative and healthy relationship. Some of the challenges of this stage include:

· Transitioning into the new family system.

· Including your spouse in your relationships with friends and family members.

· Being committed to making your marriage work.

· Putting the needs of another ahead of your own.

You and your spouse will have less stress if the transition into a new family system is smooth, and less stress often means better health.

Your specific goals for this stage of the family life cycle are:

· Forming a new family with your spouse.

· Realigning your relationships with your family of origin and your friends to now include your spouse.

Parenting: Babies Through Adolescents

Making the decision to have a baby

At some point in your marriage, you and your spouse will face the "baby decision," although some couples know going into a marriage that they do not want children. Parenting is one of the most challenging phases of the family life cycle.

The decision to have children is one that affects your individual development, the identity of your family, and your marital relationship. Children are so time-consuming that skills not learned in previous stages will be difficult to pick up at this stage. Your ability to communicate well, maintain your relationships, and solve problems are often tested during this stage.

Introducing a child into your family results in a major change in roles for you and your spouse. Each parent has three distinct and demanding roles: as an individual, a spouse, and a parent. As new parents, your individual identities shift along with how you relate to each other and to others. If you have not learned compromise and commitment in the previous stage, you may not possess the skills you need to transition well into this stage.

Along with the joy that comes from having a child, you may feel a great deal of stress and fear about these changes. A woman might have concerns about being pregnant and going through childbirth. Fathers tend to keep their fears and stress to themselves, which can cause health problems.

Discussing your emotional or physical concerns with your family physician, obstetrician, or counselor can help you deal with these and future challenges.

Parenting young children

Adapting children into other relationships, including your marriage, is a key emotional process of this stage. You will take on the parenting role and transition from being a member of a couple to being a parent. While you are still evolving as individuals, you and your spouse are also becoming decision makers for your family. Continuing to express your individuality while working well together as a couple results in a strong marriage.

Your child's healthy development depends on your ability to provide a safe, loving, and organized environment. Children benefit when their parents have a strong marriage.

Caring for young children cuts into the amount of time you might otherwise spend alone or with your spouse. If there were skills you didn't learn in previous phases, such as compromise for the good of the family, your marriage may suffer. Divorce and extramarital affairs often occur during the raising of small children when the parents have not learned proper life skills.

However, for those who have the proper tools, this can be a very rewarding, happy time, even with all of its challenges. Optimally, you develop as an individual and as a member of a couple and a family.

Specific goals when young children join your family are:

· Adjusting your marital system to make space for children.

· Taking on parenting roles.

· Realigning your relationships with your extended family to include parenting and grandparenting roles.

Parenting adolescents

Parenting teenagers can be a rough time for your family and can test your relationship skills. It's also a time for positive growth and creative exploration for your entire family. Families that function best during this period have strong, flexible marriages developed through good communication, problem solving, mutual caring, support, and trust.

Most teens experiment with different thoughts, beliefs, and styles, which can cause family conflict. Your strengths as an individual and as part of a couple are critical as you deal with the increasing challenges of rearing a teenager. Strive for a balanced atmosphere in which your teenager has a sense of support and emotional safety as well as opportunities to try new behaviors. An important skill at this stage is flexibility as you encourage your child to become independent and creative. Establish boundaries for your teenager while at the same time encouraging exploration.

If you properly developed your individual identity in earlier stages of your life, you will be much more secure about the changes your child is going through. However, if you did not fully develop the needed skills at earlier stages of life, you may feel very threatened by your child's new developments.

Flexibility in the roles each person plays in the family system is a valuable skill to develop at this stage. Responsibilities such as the demands of a job or caring for someone who is ill may require each person in the family to take on various, and sometimes changing, roles.

This is a time when one or more family members may feel some level of depression or other distress. It may also lead to physical complaints that have no physical cause (somatization disorders such as stomach upsets and some headaches) along with other stress-related disorders.

Nurturing your marriage and your individual growth can sometimes be ignored at this stage. Toward the end of this phase, a parent's focus shifts from the maturing teen to career and marriage. Neglecting your personal development and your marriage can make this shift difficult.

You also may begin thinking about your role in caring for aging parents. Making your own health a priority in this phase is helpful as you enter the next stage of the family life cycle.

Specific goals during the stage of parenting adolescents include:

· Shifting parent-child relationships to allow the child to move in and out of the family system.

· Shifting focus back to your midlife marital and career issues.

· Beginning a shift toward concern for older generations in your extended family.

Empty Nest: Launching Adult Children

The stage of launching adult children begins when your first child leaves home and ends with the "empty nest." When older children leave home, there are both positive and negative consequences. If your family has developed significant skills through the family life cycle, your children will be ready to leave home, ready to handle life's challenges. Free from the everyday demands of parenting, you may choose to rekindle your own marriage and possibly your career goals.

Developing adult relationships with your children is a key skill in this stage. You may be challenged to accept new members into your family through your children's marriages or relationships. You may focus on reprioritizing your life, forgiving those who have wronged you (maybe long ago), and assessing your beliefs about life.

If you have not moved through the phases with the appropriate tools and attitudes, you may not have taught your children needed skills to live well on their own. If you and your spouse have not transitioned together, you may no longer feel compatible with each other. Remember, however, that you can still obtain missed skills. Self-examination, education, and counseling can enhance your life and help ensure a healthy transition to the next phase.

This is a time when your health and energy levels may decline. Some people are diagnosed with chronic illnesses. Symptoms of these diseases can limit normal activities and even long-enjoyed pastimes. Health issues related to midlife may begin to occur and can include:

· High blood pressure (hypertension).

· Weight problems.

· Arthritis.

· Menopause.

· Osteoporosis.

· Heart disease (coronary artery disease).

· Depression.

· Stress-related illnesses.

You may also be caring for aging parents in this phase, which can be stressful and affect your own health.

Specific goals to attain at this stage include:

· Refocusing on your marriage without children.

· Developing adult relationships with your grown children.

· Realigning relationships to include in-laws and grandchildren when your children have begun their own families.

Retirement or Senior Stage of Life

During the retirement phase of the family life cycle, many changes occur in your life. Welcoming new family members or seeing others leave your family is often a large part of this stage as your children marry or divorce or you become a grandparent.

This stage can be a great adventure where you are free from the responsibilities of raising your children and can simply enjoy the fruits of your life's work. Challenges you may face include being a support to other family members, even as you are still exploring your own interests and activities or focusing on maintaining your marriage. Many people are caring for elderly parents at this time. You may feel challenged by their emotional, financial, and physical needs while trying to help them retain their independence.

You may experience declining physical and mental abilities or changes in your financial or social status. Sometimes, you must deal with the death of other family members, including your spouse. The quality of your life at this stage depends on how well you adjusted to the changes in earlier stages. It often also depends on how well you have cared for your own health up to this point. Normal aging will affect your body, resulting in loss of bone density, wrinkles, aches, and pains. The chances of having a mental or chronic physical illness does increase with age; however, aging does not mean you will automatically experience poor health.

Retirement can be a fulfilling and happy time. Becoming a grandparent can bring you great joy without the responsibility of raising a child. Those who are without adequate support systems or not well off financially, however, may have a more difficult time in this phase of life.

Specific goals to attain at this final stage of your family life cycle include:

· Maintaining your own interests and physical functioning, along with those of your spouse, as your body ages.

· Exploring new family and social roles.

· Providing emotional support for your adult children and extended family members.

· Making room in the family system for the wisdom and experience of older adults.

· Providing support for the older generation without overfunctioning for them.

· Dealing with the loss of a spouse, siblings, and other peers, and preparing for your own death.

· Reviewing your life and reflecting on all you have learned and experienced during your life cycle.

Concept of Family - Preventive Medicine

2009-11-11T05:46:00.000-08:00

The Concept of Family

Definition of Family

• The concept of family or the role of the family remains to be defined by universal agreement.

• Various disciplines have developed their own definition of family. Each is based on that field.

• Sociological viewpoint – enduring social form in which a person is incorporated

• Biologic viewpoint – genetic transmission unit

• Psychologic viewpoint – matrix of personality development and the most intimate emotional unit of society

A few examples of the differing definitions of family illustrate the many perspective form which people view the family.

United Nations:

• A group of people related by blood, marriages or adoption, which live together in one household.

Parsons and Bales:

• That social unity whose primary tasks are socialization of children and the stabilization of adult personalities

Ramsey and Lewis:

• A small social system made up of individuals related to each other, biologically or by reason of strong affections and loyalty, that comprises a permanent household (or cluster of households) and persists over decades. Members enter through birth, marriage or adoption and leave by death; roles of members change over time and through the history of the group.

• Common to all definitions of family are that families comprise more than one person, with at least one adult, and that these persons are related to one another by blood or social contract.

Characteristics of Family

• The family is a basic unit found in some form in all societies. It is special kind of small group which has unique characteristics different from other social system.

• The family has inherent strength because of inherited and developmental commonalities, affectional ties, and social expectations that it should operate in certain ways.

• 1. Family membership implies a lifelong involvement.

• Membership in the family unit is virtually permanent. Members are not expelled because of decrease ability to function or because of change in priorities of the family as an organization. One can never totally deny one’s parent, siblings or children.

• 2. Family relationships are primarily affectional in nature.

• Families place a higher value on caring, loving and affection than other social groups. The emotional structure of the family tends to be very strong, and family membership constitutes a fundamental part of each individual’s identity.

• 3. Family endures through time.

• Families are primary groups which endure over relatively long period of time. It is each member’s shared identification of himself as part of a family which binds that unit together rather than any specific tie such as blood, marriage or residence.

• Despite built in problems and conflicts in the family, there are bonds of affection, a sense of responsibility, and sense of belonging that continuously draw the family together.

• 4. Family members have shared attributes

• Some physical and psychological attributes are genetically influenced, so family members often have similar attributes. Living in the same home, sharing social activities, having similar schooling, and experiencing the same successes and failures give family members a common background in which they can comfortably develop.

Basic Areas of Family Function

1. Biologic

a. Child rearing/caring

b. Nutrition

c. Health maintenance

d. Recreation

e. Reproduction

Economic

Provision of adequate financial resources
Resource allocation
Ensure financial security of members

Educational

Teach, skills, attitudes relating to other function

4. Psychologic/Affection

a. Promote the natural development of personalities

b. Offer optimum psychological protection

c. Promotes ability to form relationship with people in the family circle

5. Socio-cultural

a. Socialization of children promotion of status and legitimacy

Types of Families

1. Nuclear Family

Persons and Bales, 1955:

• The members of the nuclear family, consisting of parents and their still dependent children, ordinarily occupying a separate dwelling not shared with members of the family of origin/orientation of their spouse.

• The household is in the typical case economically independent, subsiding in the first instance from the occupational earnings of the husband/father.

2. Nuclear Family Dyad

Childless husband and wife or to “empty nesters” whose children have grown and left home.

3. Extended Family

Three generations or more living in a household either unilaterally or bilaterally extended.

4. Kin Network Family

Nuclear households or unmarried members living in close geographical proximity and operating within a reciprocal system of exchange of goods and services.

5. Single Parent Family

This is consist of only one parent with one or more children, an arrangement resulting from divorce, separation, abandonment, death, adoption, never-married parent, or one parent is working away from the family (OFW’s)

6. Blended Family

Remarried men and women, living in common household with children from previous marriages. The new family also may produce offspring of its own. The media commonly refers to this form of family as “yours, mine, and ours”

7. Communal/Corporate Family

Groupings of individuals which are formed for specific ideological societal purposes. Considered as an alternative lifestyle for people who feel alienated from the predominantly economically oriented society.

Types of Communal Family:

a. Monogamous – household of more than one monogamous couple with children, sharing common facilities, resources, and appliances; socialization of the child is a group activity

b. Group marriage – household of adults and offspring known as one family, where all individuals are married to each other and all are parents to the children; usually develops a status system with leaders believed to have charisma

c. Highly formalized structures

Ex: Amish Community in Lancaster County Pennsylvania

d. Loosely knit groups

Ex: Sta. Cruz mountains near Boulder Creek in California

8. Institutional Family

Children in orphanages, residential schools, or correctional institutions

Family Social Class Patterns

Upper Class

• much more closely knit, greater concern for maintaining family name and prestige

Middle Class

• believes in hard work, initiative, independence, responsibility economic security and self-improvement through education

Lower Class

• sees life as a continuous struggle for survival, resigned to a life of frustration and defect

Characteristics of Filipino Family

1. closely knit

2. bilaterally extended

3. strong family orientation

4. authority is based on seniority/age

5. externally patriarchal, internally matriarchal

6. high value on education of children

7. predominantly Catholic (80% of population)

8. child-centered

9. average number is 5 (NEDA statistics)

10. environmental stresses: economic, political industrialization/urbanization, health problems

Tay-Sach's Disease

2009-11-11T05:40:00.000-08:00

Doctors,

Here is a brief illustration of the pathophysiology of Tay-Sach's disease. Hope it helps!

Myasthenia Gravis

2009-11-11T05:18:00.000-08:00

Introduction

Understanding the normal physiologic condition of the neuromuscular junction is a key in diagnosing and treating certain diseases such as Myasthenia Gravis and Lambert-Eaton Myasthenic Syndrome¹. In this seminar report, we will be presenting the pathologic condition of neuromuscular junction in the form of Myasthenia Gravis. Emphasis will be given to the underlying cause of the disease, its clinical manifestations and various treatments that can be used to cure or at least, lessen the severity of the disease in some cases.

Myasthenia Gravis and the Parameters in the Prediction of its Occurrence

Fauci, Braunwald and Kasper (2008) define Myasthenia Gravis as a neuromuscular disorder caused by immune-mediated loss of acetylcholine receptors characterized by weakness and fatigability of skeletal muscles. Milani and Kaminski (2006) suggest that this can be caused by circulating antibodies that block acetylcholine receptors at the post-synaptic neuromuscular junction, inhibiting the stimulative effect of the neurotransmitter acetylcholine.

Myasthenia gravis occurs in all ethnic groups and both genders. This is supported by Poulas (2000) in his study of the incidence of the disease, stating that this may occur from 3 out of 100,000 persons. It commonly affects women under 40 years of age and people from 50 to 70 years old of either sex, but it has been known to occur at any age. Kumar, Abbas and Fausto (2005) also indicated that Myasthenia Gravis is reflected with patients suffering in thymic hyperplasia and thymoma. Common risk factors are the female gender with ages 20 – 40, familial myasthenia gravis, D-penicillamine ingestion (drug induced myasthenia), and having other autoimmune diseases.

The disease may also occur in children. According to Baets (1993), 12% of the pregnancies may cause neonatal myasthenia gravis by passing the antibodies from the mother to the infant through the placenta. It can also develop at birth, known as congenital myasthenic syndrome which is not caused by an autoimmune response, but due to synaptic malformation, which in turn is caused by genetic mutations. Another form of myasthenia gravis is the Juvenile Myasthenia Gravis which occurs in childhood but after the peripartum period.

Pathophysiologic Events of the Disease

Upon discussing the normal physiologic function of the neuromuscular junction, let us now compare this to the pathophysiologic events which happen with Myasthenia Gravis.

As shown in the diagram below (refer to Diagram 1), normal neuromuscular transmission begins with action potential traveling down the motor neuron. This is initialized in the neuromuscular junction wherein acetylcholine is synthesized in the motor end terminal and stored in vesicles. When an action potential travels down a motor nerve and reaches the nerve terminal, this leads to the activation of calcium-gated channels. In turn, this will lead to an increase of the calcium levels causing the release of ACh (acetylcholine) from 150–200 synaptic vesicles into the synaptic cleft.

Afterwards, acetylcholine combines with acetylcholine receptors (AChRs) that are densely packed at the peaks of postsynaptic folds. The structure of the AChR has been fully elucidated; it consists of five subunits (2a, 1b, 1d, and 1c) arranged around a central pore (see Figure 4-A). When ACh combines with the binding sites on the subunits of the AChR, the channel in the AChR opens, permitting the rapid entry of cations, chiefly sodium, which produces depolarization at the end-plate region of the muscle fiber. If the depolarization is sufficiently large, it initiates an action potential that is propagated along the muscle fiber, triggering muscle contraction. This process is rapidly terminated by hydrolysis of ACh by acetylcholinesterase (AChE), which is present within the synaptic folds, and by diffusion of ACh away from the receptor.

Thus, Myasthenia Gravis may be associated but are not limited to risk factors such as autoimmune disease (diabetes mellitus or thyroid disease)⁵, thymus abnormalities (tumor, hyperplasia) and genetic link. Considering this initiating event, T-cells process produces ACh receptor antibodies. The antibodies are normally produced by plasma cells, derived from B cells. These B-cells convert into plasma cells by T-helper cell stimulation. In order to carry out this activation, T-helpers must first be activated themselves, which is done by binding of the T-cell receptor (TCR) to the acetylcholine receptor antigenic peptide fragment (epitope) resting within the major histocompatibility complex of an antigen presenting cells.⁶

The production of acetylcholine receptor antibodies results in decreased efficiency of neuromuscular transmission by three distinct mechanisms. First, it directly alters function of receptor by blocking the active site of the acetylcholine receptor which is the site that normally binds acetylcholine. Second, there is an accelerated turnover of AChRs by a mechanism involving cross-linking and rapid endocytosis of the receptors. This consequently accelerates the degradation of acetylcholine receptors. Third, it causes damage to the postsynaptic muscle membrane by the antibody in collaboration with complement system.³ This also leads to a decreased in the number of AChR.

An immune response to muscle-specific kinase (MuSK) can also result in myasthenia gravis, possibly by interfering with AChR clustering. MuSK antibodies inhibit the signaling of MuSK by its nerve-derived ligand, agrin. The result is a decrease in patency of the neuromuscular junction leading to decreased efficiency of the neuromuscular transmission. Therefore, although ACh is released normally, it produces small end-plate potentials that may fail to trigger muscle action potentials. Failure of transmission at many neuromuscular junctions results in weakness of muscle contraction.

During normal neurotransmission, the amount of ACh released with each impulse is reduced or declined upon repeated activity. This is termed as presynaptic rundown. In the myasthenic patient, the decreased efficiency of neuromuscular transmission combined with the normal rundown results in the activation of fewer and fewer muscle fibers by successive nerve impulses and hence increasing weakness, or myasthenic fatigue. This mechanism also accounts for the decremental response to repetitive nerve stimulation seen on electrodiagnostic testing.³ The sequence of pathophysiologic events in Myasthenia Gravis is shown in Diagram 2, which also presents the clinical manifestations of patients affected with the disease.

Clinical Manifestation of Myasthenia Gravis

The cardinal features of Myasthenia Gravis are weakness and fatigability of muscles. The weakness increases during repeated use (fatigue) and may improve following rest or sleep.³ Muscles become progressively weaker during periods of activity and improve after periods of rest. Muscles that control eye and eyelid movement, facial expression, chewing, talking, and swallowing are especially susceptible. The muscles that control breathing and neck and limb movements can also be affected. Often the physical examination is within normal limits.⁷

The onset of the disorder can be sudden. Often symptoms are intermittent. The diagnosis of myasthenia gravis may be delayed if the symptoms are subtle or variable. The distribution of muscle weakness often has a characteristic pattern. It may vary among patients, ranging from a localized form, limited to eye muscles (ocular myasthenia), to a severe or generalized form in which many muscles - sometimes including those that control breathing - are affected.

Symptoms result from weakness of the voluntary muscles innervated by the ten cranial nerves originating in the brainstem. The cranial muscles, particularly the lids and extraocular muscles, are often involved early in the course of Myasthenia Gravis, and diplopia (double vision) and ptosis (drooping of one or both eyelids) are common initial complaints.

Other symptoms are related to a change in facial expression. Facial weakness produces a "snarling" expression when the patient attempts to smile. Weakness in chewing is most noticeable after prolonged effort, as in chewing meat. Speech may have a nasal timbre caused by weakness of the palate or a dysarthric "mushy" quality due to tongue weakness. Difficulty in swallowing (dysphagia) may occur as a result of weakness of the palate, tongue, or pharynx, giving rise to nasal regurgitation or aspiration of liquids or food (Fauci, 2008).

Bulbar weakness is especially prominent in MuSK antibody–positive MG. In ~85% of patients, the weakness becomes generalized, affecting the limb muscles as well. They vary from person to person, but can include severe fatigue, an unstable or waddling gait, weakness in the arms resulting in an inability to raise the arms over the head, and proximal limb weakness e.g. affecting the hands and fingers. If weakness remains restricted to the extraocular muscles for 3 years, it is likely that it will not become generalized, and these patients are said to have ocular Myasthenia Gravis. The limb weakness in Myasthenia Gravis is often proximal and may be asymmetric. Despite the muscle weakness, deep tendon reflexes are preserved (Fauci, 2008).

Muscle weakness may develop over a few days or weeks, or remain at the same level for long periods. Repeated use resulting to fatigue may be partially alleviated by rest or sleep, while it tends to worsen with exercise and at the end of the day. Symptoms in female patients are often more severe during menses and pregnancy. Exacerbations and remissions may occur, particularly during the first few years after the onset of the disease. Remissions are rarely complete or permanent. Unrelated infections or systemic disorders often lead to increased myasthenic weakness and may precipitate "crisis".

In myasthenic crisis a paralysis of the respiratory muscles occurs, necessitating assisted ventilation to sustain life. It usually consists of respiratory failure caused by diaphragmatic and intercostal muscle weakness.³ In patients whose respiratory muscles are already weak, crises may be triggered by infection, fever, an adverse reaction to medication, or emotional stress.⁸ Since the heart muscle is stimulated differently, it is never affected by Myasthenia Gravis.

Classification of Myasthenia Gravis

Based on Jaretzki (2000), the most widely accepted classification of myasthenia gravis is the Myasthenia Gravis Foundation of America Clinical Classification:

Class I: Any eye muscle weakness, possible ptosis, no other evidence of muscle weakness elsewhere
Class II: Eye muscle weakness of any severity, mild weakness of other muscles

Class IIa: Predominantly limb or axial muscles
Class IIb: Predominantly bulbar and/or respiratory muscles

Class III: Eye muscle weakness of any severity Moderate weakness of other muscles

Class IIIa: Predominantly limb or axial muscles
Class IIIb: Predominantly bulbar and/or respiratory muscles

Class IV: Eye muscle weakness of any severity, severe weakness of other muscles

Class IVa: Predominantly limb or axial muscles
Class IVb: Predominantly bulbar and/or respiratory muscles (Can also include feeding tube without intubation)

Class V: Intubation needed to maintain airway

Clinical Treatment for Myasthenia Gravis

The prognosis has improved strikingly as a result of advances in treatment; virtually all myasthenic patients can be returned to full productive lives with proper therapy. The most useful treatments for MG include anticholinesterase medications, immunosuppressive agents, thymectomy, and plasmapheresis or intravenous immunoglobulin.

The treatment for Myasthenia Gravis discussed in this seminar report is taken from Harrison’s Principles of Internal Medicine by A. Fauci and D. Longo (2008), which is briefly summarized. The following treatments taken from the book are medications such as anticholinesterase and immunosuppressive drugs, surgery (thymectomy), plasmapheresis and management of myasthenic crisis.

A. Medications

Acetylcholinesterase inhibitors produce at least partial improvement in most myasthenic patients, although improvement is complete in only a few. Pyridostigmine is the most widely used anticholinesterase drug. As a rule, the beneficial action of oral pyridostigmine begins within 15–30 min and lasts for 3–4 h, but individual responses vary. Treatment is begun with a moderate dose, e.g., 30–60 mg three to four times daily. The frequency and amount of the dose should be tailored to the patient's individual requirements throughout the day. Neostigmine can also improve muscle function by slowing the natural enzyme cholinesterase that degrades acetylcholine in the motor end plate. In some patients, muscarinic side effects of the anticholinesterase medication (diarrhea, abdominal cramps, salivation, nausea) may limit the dose tolerated.

Immunosuppression using glucocorticoids, azathioprine, and other drugs is effective in nearly all patients with MG. Glucocorticoids, when used properly, produce improvement in myasthenic weakness in the great majority of patients. To minimize adverse side effects, prednisone should be given in a single dose rather than in divided doses throughout the day. The initial dose should be relatively low (15–25 mg/d) to avoid the early weakening that occurs in about one-third of patients treated initially with a high-dose regimen. For the intermediate term, glucocorticoids and cyclosporine or tacrolimus generally produce clinical improvement within a period of 1–3 months. The beneficial effects of azathioprine and mycophenolate mofetil usually begin after many months (up to a year), but these drugs have advantages for the long-term treatment of patients with MG.

B. Surgery

Two separate issues should be distinguished: (1) surgical removal of thymoma, and (2) thymectomy as a treatment for MG. Surgical removal of a thymoma is necessary because of the possibility of local tumor spread, although most thymomas are histologically benign. In the absence of a tumor, the available evidence suggests that up to 85% of patients experience improvement after thymectomy; of these, ~35% achieve drug-free remission. However, the improvement is typically delayed for months to years. The advantage of thymectomy is that it offers the possibility of long-term benefit, in some cases diminishing or eliminating the need for continuing medical treatment.

C. Plasmapheresis

Plasmapheresis has been used therapeutically in MG. Plasma, which contains the pathogenic antibodies, is mechanically separated from the blood cells, which are returned to the patient. A course of five exchanges (3–4 L per exchange) is generally administered over a 10- to 14-day period. Plasmapheresis produces a short-term reduction in anti-AChR antibodies, with clinical improvement in many patients.

Brainstem - Neuroanatomy Transcription

2009-11-11T04:41:00.000-08:00

Brainstem is made up of:

Medulla Oblongata
Pons
Midbrain

Occupies the: Posterior Cranial Fossa of the Skull

* Stalklike in shape

* Connects the narrow spinal cord with the expanded forebrain

Broad Functions:

1. Serves as a conduit for the ascending tracts and descending tracts connecting the spinal cord to the different parts of the higher centers in the forebrain

2. Contains important reflex centers associated with the control of respiration and the cardiovascular system; also associated with the control of consciousness

3. Contains important nuclei of cranial nerves III through XII

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GROSS APPEARANCE OF THE MEDULLA OBLONGATA

* Medulla Oblongata connects the pons superiorly with the spinal cord interiorly

* Junction of the medulla and spinal cord

° located at the origin of the anterior and posterior roots of the first cervical spinal nerve corresponding to the level of foramen magnum

* Conical in shape

* Broad extremity being directed superiorly

* Central Canal

° Continues upward into the lower half of the medulla

° In upper half it expands as the cavity of the 4^th ventricle

* Anterior Median Fissure

° Located at the anterior surface if the medulla

° Continuous inferiorly with the anterior median fissure of the spinal cord

* Pyramid

° Swelling located on each side of the median fissure

° Composed of bundles of nerve fibers, corticospinal fibers, which originate in large nerve cells in the precentral gyrus of the cerebral cortex

° Taper inferiorly

° It is here that majority of the descending fibers cross over the opposite side, forming the decussation of the pyramids

* Anterior external arcuate fibers

° Few nerve fibers that emerge from anterior medial fissure above the decussation and pass laterally over the surface of the medulla oblongata to enter the cerebellum

* Olives

° Posterolateral to the pyramids

° Oval elevations produced by the underlying inferior olivary nuclei

* Rootlets of the hypoglossal nerve

° Emerge in the groove between the pyramid and the olive

* Inferior Cerebellar Peduncles

° Posterior to the olives

° Connect the medulla to the cerebellum

* Roots of the glossopharyngeal and vagus nerves and cranial roots of accessory nerve

° Emerge in the groove between the olive and the inferior cerebellar peduncle

* Floor of the fourth ventricle

° Lower part is formed by the posterior surface of the superior half of the medulla oblongata

* Posterior Medial Sulcus

° Possessed by the posterior surface of the inferior half of the medulla which is continuous with the posterior aspect of the spinal cord

* Gracile Tubercle

° Elongated swelling on each side of median sulcus

° Produced by the underlying gracile nucleus

* Cuneate Tubercle

° Lateral to the gracile tubercle

° Similar swelling as the gracile tubercle

° Produced by the underlying cuneate nucleus

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INTERNAL STRUCTURE

Medulla Oblongata consists of white and gray matter but have been extensively rearranged

Explanation:

This rearrangement is due to the expansion of the neural tube to form the hindbrain vesicle
This hindbrain vesicle becomes the 4^th ventricle
The extensive lateral spread of the 4^th ventricle results in alteration in the position of the derivatives of the alar and basal plates of the embryo

To assist in understanding this concept:

Remember!

In the Spinal cord In Medulla Oblongata

derivatives Posterior to sulcus limitans lateral to sulcus limitans

of alar plates

derivatives anterior to sulcus limitans medial to sulcus limitans

of basal plates

4 Levels of the internal structure of the medulla oblongata

Level of decussation of pyramids
Level of decussation of lemnisci
Level of the olives
Level just inferior to the pons

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LEVEL OF DECUSSATION OF PYRAMIDS

* Great Motor Decussation

* Where a transverse section through the inferior half of the medulla oblongata passes through

* In superior part of the medulla: corticospinal fibers occupy and form the pyramid

* Inferiorly: about ¾ of the fibers cross the medial plane and continue down the spinal cord in the lateral white column as the lateral corticospinal tract

° As these fibers cross the midline, they sever the continuity between the anterior column of the gray matter of the spinal cord and the gray matter that surrounds the central canal

* Fasciculus gracilis and the fasciculus cuneatus

° Continue to ascend superiorly posterior to the central gray matter

* Nucleus gracilis and nucleus cuneatus

°Appear as posterior extensions of the central gray matter

* Substantia gelatinosa in posterior gray column of the spinal cord

° Becomes continuous with the inferior end of the nucleus of the spinal tract of the trigeminal nerve

* The fibers of the tract of the nucleus

° Situated between the nucleus and the surface of the medulla oblongata

° The lateral and anterior white columns of the spinal cord are easily identified in these sections and their fiber arrangement is unchanged

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LEVEL OF DECUSSATION OF LEMNISCI

* The Great Sensory Decussation

* Where a transverse section through the inferior half of the medulla oblongata, a short distance above the level of the decussation of the pyramids passes through

* Takes place anterior to the central gray matter and posterior to the pyramids

* The lemnisci have been formed from the internal arcuate fibers

* Internal arcuate fibers

° Emerged from the anterior aspects of the nucleus gracilis and nucleus cuneatus

° First travel anteriorly and laterally around the central gray matter

° They then curve medially toward the midline, where they decussate with the corresponding fibers of the opposite side.

* Nucleus of the spinal tract of the trigeminal nerve

° Lies lateral to the internal arcuate fibers

° Spinal tract of the trigeminal nerve lies lateral to the nucleus

* Lateral and Spinothalamic tracts and Spinotectal tracts

° Occupy an area lateral to the decussation of the lemnisci

° They are very close to one another and collectively known as the spinal lemniscus

* Situated in the anterolateral region of medulla oblongata:

° Spinocerebellar, vestibulospinal, rubrospinal tracts

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LEVEL OF OLIVES

* A transverse section through the olives passes across the inferior part of the 4^th ventricle

* The amount of gray matter has increased owing to the presence of the olivary nuclear complex:

° Nuclei of vestibulocochlear

° Glossopharyngeal

° Vagus

° Accessory

° Hypoglossal nerves

° Arcuate nuclei

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OLIVARY NUCLEAR COMPLEX

Inferior Olivary nucleus – Largest nucleus of this complex

* Gray matter – shaped like a crumpled bag with its mouth directed medially

- Responsible for the elevation on the surface of the medulla called, olive

* Smaller dorsal and medial accessory olivary nuclei are also present

* Cells of the inferior olivary nucleus send fibers medially across the midline to enter the cerebellum through the inferior cerebellar peduncle

* Afferent fibers reach the inferior olivary nuclei from the spinal cord (spino-olivary tracts) and from the cerebellum and cerebral cortex

* Function of the olivary nuclei: Associated with voluntary muscle movement

VESTIBULOCOCHLEAR NUCLEI

Made up of the following nuclei:

Medial vestibular nucleus
Inferior vestibular nucleus
Lateral vestibular nucleus
Superior vestibular nucleus

Cochlear nuclei - two in number

Anterior Cochlear nucleus - situated on the anterolateral aspect of the inferior cerebellar peduncle

Posterior Cochlear nucleus - situated on the posterior aspect of the peduncle lateral to the floor of the 4^th ventricle

NUCLEUS AMBIGUUS

* Consists of large motor neurons

* Situated deep within the reticular formation

* The emerging nerve fibers join the glossopharyngeal vagus, and cranial part of the accessory nerve and are distributed to voluntary skeletal muscle

* Deeply placed within the reticular formation

CENTRAL GRAY MATTER

* Lies beneath the floor of the 4^th ventricle

* Passes from medial to lateral

* The following important structures may be recognized:

1. Hypoglossal nucleus

2. Dorsal nucleus of the vagus

3. Nucleus of the tractus solitarius

4. Medial and inferior vestibular nuclei

* Arcuate nuclei

° Thought to be inferiorly displaced pontine nuclei

° Situated on the anterior surface of the pyramids

° They receive nerve fibers from the cerebral cortex

° Send efferent fibers to the cerebellum through the anterior external arcuate fibers

* Pyramids containing the corticospinal and some corticosnuclear fibers

° Situated in the anterior part of the medulla

° Separated by the anterior median fissure

° Corticospinal fibers descend to the spinal cord

° Corticonuclear fibers are distributed to the motor nuclei of the cranial nerves situated within the medulla

* Medial Lemniscus

° Forms a flattened tract on each side of the midline posterior the pyramid

° These fibers emerge from the decussation of the lemnisci and convey sensory information to the thalamus

* Medial Longitudinal Fasciculus

° Forms a small tract of nerve fibers situated on each side of the midline posterior to medial lemniscus and anterior to hypoglossal nucleus

° Consists of ascending and descending fibers

* Inferior Cerebellar Peduncle

° Situated in posterolateral corner of the section on lateral side of 4^th ventricle

* Spinal tract of trigeminal nerve and its nucleus

° Situated on the anteromedial aspect of the inferior cerebellar peduncle

* Anterior Spinocerebllar Tract

° Near the surface in the interval between the inferior olivary nucleus and the nucleus of the spinal tract of the trigeminal nerve

* Spinal Lemniscus

° Deeply placed

° Consists of:

Anterior Spinothalamic

Lateral Spinothalamic

Spinotectal tracts

Reticular formation

° Consists of a diffuse mixture of nerve fibers and small groups of nerve cells

° Deeply placed posterior to the olivary nucleus

° Represents, at this level, only a small part of this system, which is also present in the pons and midbrain

Glossopharyngeal

Vagus can be seen running forward and

Cranial part of the accessor nerves laterally through the reticular formation

* The nerve fibers emerge between the olives and the inferior cerebellar peduncles

Hypoglossal nerves

° Run anteriorly and laterally through the reticular formation and emerge between the pyramids and the olives

LEVEL JUST INFERIOR TO THE PONS

° No major changes

° Lateral vestibular nucleus has replaced the inferior vestibular nucleus

° Cochlear nuclei now are visible on the anterior and posterior surfaces of the inferior cerebellar peduncle

GROSS APPEARANCE OF THE PONS

* Pons is anterior to the cerebellum

* Connects the medulla oblongata to the midbrain

* About 1 inch (2.5 cm) long

* Owes its name to the appearance presented on the anterior surface, which is that of a bridge connecting the right and left cerebellar hemispheres

* Anterior surface

° Convex from side to side

° Shows many transverse fibers that converge on each side to form the middle cerebellar peduncle

* Basilar groove

° Shallow groove in the midline

° Lodges the basilar artery

* Anterolateral surface of the pons

° trigeminal nerve emerges on each side

° Each nerve consist of:

Smaller, medial part – the motor root

Larger, lateral part – sensory root

* In the groove between the pons and medulla oblongata

° There emerge from medial to lateral:

abducent, facial, and vestibulocochlear nerves

* the Posterior surface of the pons

° hidden from view

° Forms the upper half of the floor of the 4^th ventricle

° Triangular in shape

° Limited laterally by the superior cerebellar peduncles

° Divided into symmetrical halves by a median sulcus

° Lateral to this sulcus is an elongated elevation, the medial eminence

° Medial eminence is bounded laterally by the sulcus limitans and its inferior end is slightly expanded to form the facial colliculus

° Facial colliculus is produced by the root of the facial nerve winding around the nucleus of the abducent nerve

° The floor of the superior part of the sulcus limitans is bluish gray in color and is called the substantia ferruginea (it owes its color to a group of deeply pigmented nerve cells)

° Lateral to the sulcus limitans is the area vestibuli produced by the underlying vestibular nuclei

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INTERNAL STRUCTURE OF THE PONS

Divisions of the pons:

1. Tegmentum - posterior part

2. Basal part – anterior part by the transversely running fibers of the trapezoid body

The structure of the pons may be studied at two levels:

Transverse section through the caudal part

Passing through the facial colliculus

Transverse section through the cranial part

Passing through the trigeminal nuclei

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TRANSVERSE SECTION THROUGH THE CAUDAL PART

Medial lemniscus

Rotates as it passes from the medulla into the pons
Situated in the most anterior part of the tegmentum with its long axis running transversely
Accompanied by the spinal and lateral lemnisci

Facial nucleus

Lies posterior to the lateral part of the medial lemniscus
The fibers of the facial nerve wind around the nucleus of the abducent nerve, producing the facial colliculus

Fibers of the facial nerve pass anteriorly between the facial nucleus and the superior end of the nucleus of the spinal tract of the trigeminal nerve

Medial longitudinal fasciculus

Situated beneath the floor of the 4^th ventricle on either side of the midline
Main pathway that connects the vestibular and cochlear nuclei with the nuclei controlling the extraocular muscles (oculomotor, trochlear, and abducent nuclei)

Medial Vestibular nucleus

Situated lateral to the abducent nucleus
In close relationship to the inferior cerebellar peduncle
Where the superior part of the lateral and the inferior part of the superior vestibular nucleus are located
Posterior and anterior cochlear nuclei are also found at this level

Spinal Nucleus of the trigeminal nerve

Lie on the anteromedial aspect of the inferior cerebellar peduncle

Trapezoid body

Made up of fibers derived from the cochlear nuclei and the nuclei of the trapezoid body
Run transversely in the anterior part of the tegmentum

Pontine Nuclei

Small masses of nerve cells contained in the basilar part of the pons

Corticopontine fibers of the crus cerebri of the midbrain

Terminate in the pontine nuclei
Axons of these cells gives origin to the transverse fibers of the pons

Transverse fibers of the pons

Cross the midline and intersect the corticospinal and corticonuclear tracts, breaking them up into small bundles
Enter the middle cerebellar peduncle
Distributed to the cerebellar hemisphere
This connection forms the main pathway linking the cerebral cortex to the cerebellum

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TRANSVERSE SECTION THROUGH THE CRANIAL PART

* Internal structure is similar to that seen at the caudal levels

* But it now contains the motor and principal sensory nuclei of the trigeminal nerve

Motor nucleus of the trigeminal nerve

Situated beneath the lateral part of the 4^th ventricle within the reticular formation
Emerging motor fibers travel anteriorly through the substance of the pons and exit on its anterior surface

Principal sensory nucleus of the trigeminal nerve

Situated on the lateral side of the motor nucleus
Continuous inferiorly with the nucleus of the spinal tract
Entering sensory fibers travel through the substance of the pons and lie lateral to the motor fibers

Superior Cerebellar peduncle

Situated posterolateral to the motor nucleus of the trigeminal nerve
Joined by the anterior spinocerebellar tract

Trapezoid body and medial lemniscus

Situated in the same position as they were in the previous section

Lateral and spinal lemnisci

Lies at the lateral extremity of the medial lemniscus

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GROSS APPEARANCE OF THE MIDBRAIN

* 0.8 inch (2 cm) in length

* Connects the pons an dcerebellum with the forebrain

* Its long axis inclines anteriorly as it ascends through the opening in the tentorium cerebelli

Cerebral Aqueduct

narrow channel traversing the midbrain
filled with CSF

Four colliculi

Corpora quadrigemina
Found on the posterior surface
Rounded eminences that are divided into superior and inferior pairs by a vertical and a transverse groove

Superior Colliculi Inferior Colliculi

Centers for visual reflexes Lower auditory centers

Trochlear nerves

Emerging from the midline below the inferior colliculi
Small diameter nerves that wind around the lateral aspect of the midbrain to enter the lateral wall of the cavernous sinus

* The superior and inferior brachia ascend in an anterolateral direction on the lateral aspect of the midbrain

Superior brachium

Passes from the superior colliculus to the lateral geniculate body and the optic tract

Inferior brachium

Connects the inferior colliculus to the medial geniculate body

* On anterior aspect of midbrain

There’s a deep depression in the midline the interpeduncular fossa
interpeduncular fossa

Bounded on either side by the crus cerebri
Floors are perforated by many blood vessels and this region is termed the posterior perforated substance

Oculomotor nerve

Emerges from a groove on the medial side of the crus cerebri
Passes forward in the lateral wall of the cavernous sinus

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INTERNAL STRUCTURE OF THE MIDBRAIN

2 lateral halves of midbrain: Cerebral peduncles

Each divided into

- an anterior part: the Crus cerebri

- posterior part: Tegmentum

Division is made possible by substantia nigra, pigmented band of gray matter

Cerebral aqueduct

Narrow cavity of the midbrain
Connects the 3^rd and 4^th ventricle

Tectum

Part of the midbrain posterior to the cerebral aqueduct
Has four small surface swellings referred to previously

2 superior and 2 inferior colliculi

Central gray matter

Surrounds the cerebral aqueduct (lined by ependyma)

Interpeduncular fossa on transverse sections of the midbrain

Can be seen to separate the crura cerebri
Whereas the tegmentum is continuous across the median plane

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TRANSVERSE SECTION OF THE MIDBRAIN AT THE LEVEL OF THE INFERIOR COLLICULI

Inferior colliculus

Consists of a large nucleus of gray matter
Lies beneath the corresponding surface elevation
Forms part of the auditory pathway
Receives many of the terminal fibers of the lateral lemniscus
Pathway then continues through the inferior brachium to the medial genicualte body

Trochlear nucleus

Situated in the central gray matter close to the median plane
Posterior to the medial longitudinal fasciculus

Emerging fibers pass laterally and posteriorly around the central gray matter
Leave the midbrain just below the inferior colliculi
Fibers of the trochlear nerve now decussate completely in the superior medullary velum

* Mesencephalic nuclei of the trigeminal nerve

° Lateral to the cerebral aqueduct

* The Decussation of the superior cerebellar peduncles

° Occupies the central part of the tegmentum anterior to the cerebral aqueduct

*Reticular formation

° Smaller than that of the pons

° Situated lateral to the decussation

Medial lemniscus – ascends posterior to the substantia nigra

Spinal and trigeminal lemnisci – situated lateral to the medial lemniscus

Lateral Lemniscus – located posterior to the trigeminal lemniscus

Substantia Nigra

° Large motor nucleus

° Situated between the tegmentum and the crus cerebri

° Found throughout the midbrain

° Nucleus is composed of medium sized multipolar neurons that possess inclusion granules of melanin pigment within their cytoplasm

° Concerned with muscle tone

° Connected to the cerebral cortex, spinal cord, hypothalamus and basal nuclei

Crus cerebri

° Contains important descending tracts

° Separated from the tegmentum by the substantia nigra

° Middle 2/3 is occupied by the corticospinal and corticonulcear fibers

° Medial part is occupied by the frontopontine fibers

° Lateral part occupied by the temporopontine fibers

* These descending tracts connect the cerebral cortex to the anterior gray column cells of the spinal cord, cranial nerve nuclei, pons, and cerebellum

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TRANSVERSE SECTION OF THE MIDBRAIN AT THE LEVEL OF THE SUPERIOR COLLICULI

Superior colliculus

Large nucleus of gray matter that lies beneath the corresponding surface elevation
Forms part of the visual reflexes
Connected to the lateral geniculate body by the superior brachium
It receives afferent fibers from the optic nerve, the visual cortex and the spinotectal tract
Efferent fibers

Form the tectospinal and tectobulbar tracts,

Responsible for the reflex movements of the eyes, head, and neck in response to visual stimuli

Afferent pathway for the light reflex ends in the pretectal nucleus

This is small group of neurons situated close to the lateral part of the superior colliculus
After relaying in the pretectal nucleus, the fibers pass to the parasympathetic nucleus of the oculomotor nerve (Edinger-Westphal nucleus)

The emerging fibers then pass to the oculomotor nerve.

Oculomotor nucleus

Situated in the central gray matter close to the median plane, just posterior to the medial longitudinal fasciculus
The fibers pass anteriorly through the red nucleus to emerge on the medial side of the crus cerebri in the interpeduncular fossa
Nucleus of the oculomotor nerve is divisible into a number of cells group

* Medial, spinal, and trigeminal lemnisci

Form a curved band posterior to the substantia nigra

* Lateral lemniscus

Does not extend superiorly to this level

Red nucleus

Rounded mass of gray matter
Situated between the cerebral aqueduct and the substantia nigra
Reddish hue seen in fresh specimen

Due to its vascularity and the presence of an iron-containing pigment in the cytoplasm of many its neurons

Afferent fibers reach the red nucleus from

Cerebral cortex through the corticospinal fibers
Cerebellum through the superior cerebellar peduncle
Lentiform nucleus, subthalamic and hypothalamic nuclei, substantia nigra, and spinal cord

Efferent fibers leave the red nucleus and pass to

Spinal cord through the rubrospinal tract (as this tract descends, it decussates)
Reticular formation through the rubroreticular tract
Thalamus
Substantia nigra

Reticular formation

Situated in the tegmentum lateral and posterior to the red nucleus

Crus cerebri

Contains the identical important descending tracts,

The corticospinal, corticonuclear and corticopontine fibers

Present at the level of the inferior colliculus

Cerebrum - Neuroanatomy Transcription

2009-11-11T04:28:00.000-08:00

CHAPTER 7

SUBDIVISIONS OF THE CEREBRUM

Cerebrum – largest part of the brain

- Situated in the anterior and middle cranial fossae of the skull, occupying its whole cavity

- May be divided into two parts:

o Diencephalon – forms central core

o Telencephalon – forms cerebral hemispheres

DIENCEPHALONS

- Consists of the third ventricle and its boundaries

- Extends posteriorly where third ventricle is continuous with the cerebral aqueduct, and anteriorly as far as the interventricular foramina

- Midline structure with symmetrical right and left halves

Gross Features

Inferior surface

- Only area exposed to the surface in the intact brain

- Formed by the hypothalamic and other structures, including (from anterior to posterior):

o Optic chiasma – with optic tract on either side

o Infundibulum – with tuber cinereum

o Mammillary bodies

Superior surface

- Concealed by the fornix

o Fornix – thick bundle of fibers that originates in the hippocampus of the temporal lobe and arches posteriorly over the thalamus to join the mammillary body

- Actual superior wall is formed by the roof of the third ventricle

o Consists of ependyma

o Covered superiorly by a vascular fold of pia mater, called tela choroidea of the third ventricle

- From the roof of the third ventricle a pair of vascular processes, the choroid plexuses of the third ventricle, project downward from the midline cavity of the third ventricle

Lateral Surface

- Bounded by the internal capsule of white matter

- Consists of nerve fibers that connect the cerebral cortex with other parts of the brainstem and spinal cord

Medial Surface

- Since the diencephalons is divided into symmetrical halves by the slitlike third ventricle, it also has a medial surface

- Formed in its superior part by the medial surface of the thalamus and in its inferior part by the hypothalamus

- These two areas are separated from one another by a shallow sulcus, the hypothalamic sulcus

- Stria medullaris thalami

o Bundle of nerve fibers

o Afferent fibers to the habenular nucleus

o Forms a ridge along the superior margin of the medial surface of the diencephalons

The diencephalons can be divided into four parts:

Thalamus
Subthalamus
Epithalamus
hypothalamus

Thalamus

- Large ovoid mass of gray matter that forms the major part of the diencephalon

- It is a region of great functional importance

- Serves as a cell station to all the main sensory systems (except the olfactory pathways)

- Situated on each side of the third ventricle

Anterior end of thalamus

- Narrow and rounded

- Forms the posterior boundary of the interventricular foramen

Posterior end of thalamus

- Expanded to form the pulvinar, which overhangs the superior colliclus and the superior brachium

- Lateral Geniculate Body

o Forms a small elevation on the under aspect of the lateral portion of the pulvinar

Superior surface of the thalamus

- Covered medially by the tela choroidea and the fornix

- Laterally covered by the ependyma and forms part of the floor of the lateral ventricle,

- Lateral part is hidden by the choroids plexus of the lateral ventricle

Inferior surface

- Continuous with the tegmentum of the midbrain

Medial surface of the thalamus

- Forms the superior part of the lateral wall of the third ventricle

- Usually connected to the opposite thalamus by a band of gray matter, the interthalamic connection (interthalamic adhesion)

Lateral surface of the thalamus

- Separated from the lentiform nucleus by the very important band of white matter called, internal capsule

The thalamus

Very important cell station
Receives the main sensory tracts 9excpet olfactory pathway)
Station where much of the information is integrated and relayed to the cerebral cortex and many other subcortical regions
Key role in the integration of visceral and somatic functions

Subthalamus

- Lies inferior to the thalamus

- Situated between the thalamus and tegmentum of the midbrain

- Craniomedially, it is related to hypothalamus

- Complex structure

- Among the collection of nerve cells found in the subthalamus are the:

o Cranial ends of the red nuclei and the substantia nigra

- Shape of a biconvex lens

- Nucleus connected with the corpus striatum and involved in the control of muscle activity

- Contains many important tracts that pass up from the tegmentum to the thalamic nuclei. Ex. Cranial ends of the medial, spinal, and trigeminal lemnisci

Epithalamus

- Consists of :

o Habenular nuclei and their connections

o Pineal gland

Habenular nucleus

- Small group of neurons situated just medial to the posterior surface of the thalamus

- Afferent fibers received from the amygdaloid nucleus in the temporal lobe through stria medullaris thalami

- Other fibers pass from hippocampal formation through the fornix

- Some reach habenular nucleus of opposite side forming habenular commissure

- Axons pass to the interpeduncular nucleus in the roof of the interpeduncular fossa, tetcum of midbrain, thalamus and reticular formation of midbrain

- Center for integration of olfactory, visceral and somatic afferent pathways

PINEAL GLAND (BODY)

- small, conical, structure attached to pineal stalk to the diencephalons

- projects backward so that it lies to the midbrain

- the base possesses a recess continuous with the cavity of the third ventricle

- superior part of the base of the stalk contains habenular commissure

- inferior part contains posterior commissure

- seen to be incompletely divided into lobules by connective tissue septa extending into the substance of the gland from the capsule

- 2 types of cells found in the gland:

o pinealocytes

o glial cells

- brain sands- concretions of calcified material progressively accumulating within the pineal gland with age

- no nerve cells

- adrenergic sympathetic fibers derived from the superior cervical sympathetic ganglia enter the gland and run in association with the blood vessels and pinealocytes

- influence activities of pituitary gland, islets of langerhans of pancreas, parathyroids, adrenals, and gonads

Functions of pineal gland

- pineal secretions actions are mainly inhibitory and either directly inhibit production of hormones or indirectly inhibit secretion of releasing factors by hypothalamus

- Pineal gland DOES NOT POSSESS A BBB

- Pineal activity exhibits a circadian rhythm influenced by light

- Gland has been found to be most active during darkness

- Probable nervous pathway from the retina

o 1^st: runs to suprachiasmatic nucleus of hypothalamus

o 2^nd tegmentum of midbrain

o 3^rd pineal gland to stimulate its secretions

§ may include reticulospinal tract, sympathetic outflow of thoracic part of spinal cord, superior cervical sympathetic ganglion and postganglionic nerve fibers that travel to pineal gland and blood vessels

- Melatonin and enzymes present in high concentrations

o Released into blood and CSF of third ventricle and pass to anterior lobe of pit. Gland and inhibit release of gonadotrophic hormone

o In humans: Plasma melatonin level rises in darkness and falls during the day

- Regulation of reproductive function

HYPOTHALAMUS

- Part of the diencephalons that extends from the region of the optic chiasma to the caudal border of the mammillary bodies

- Lies below the hypothalamic sulcus on the lateral wall of the third ventricle

- Strategically well placed close to the limbic system, the thalamus, the ascending and descending tracts, and the hypophysis

- Microscopically, the hypothalamus is composed of small nerve cells arranged in groups or nuclei

- Physiologically, there is hardly any activity in the body that is not influenced by the hypothalamus

- Controls and integrates the functions of the ANS and ES and plays vital role in body homeostasis

- Involved in such activities as regulation of body temperature, body fluids, dives to eat and drink , sexual behavior, and emotion

Relations of the hypothalamus

- Anterior to hypothalamus is an area that extends forward from the optic chiasma to the lamina terminalis and anterior commissure, referred tp as the preoptic area

- Caudally, it merges into the tegmentum of the midbrain

- Superior to the hypothalamus lies the thalamus and inferolaterally is the subthalamic region

- When seen from below it is related to the following structures, from anterior to posteriot:

o Optic chiasma

o Tuber cinereum

o Infundibulum

o Mammillary bodies

OPTIC CHIASMA

- Flattened bundle of nerve fibers situated at the junction of the anterior wall and floor of the third ventricle

- Superior surface attached to lamina terminalis

- Inferiorly related to hypophysis cerebri, from which it is separated by the diaphragma sellae

- Anterolateral corners of chiasma are continuous with optic nerves and posterolateral corners with optic tracts

- Optic recess of the third ventricle, a small recess lies on its superior surface

- Fibers originating from the nasal half of each retina cross the median plane at the chiasma to enter the optic tract of the opposite side

TUBER CINEREUM

- convex mass of gray matter

- continuous inferiorly with the infundibulum

- Infundibulum

o hollow and continuous with the posterior lobe of the hypophysis cerebri

- Median eminence

o Raised part of the tuber cinereum to which is attached the infundibulum

o Neurohypophysis is formed by:

§ Median eminence

§ Imfundibulum

§ Posterior lobe (pars nervosa) of hypophysis cerebri

MAMMILLARY BODIES

- 2 small hemispherical bodies situated side by side posterior to the cinereum

- possess a central gray core of gray matter invested by a capsule of myelinated nerve fibers

- Posterior to mammillary bodies lies an area of the brain that is pierced by a number of small apertures and is called posterior perforated substance --- transmit the central branches of the posterior cerebral arteries

THIRD VENTRICLE

- derived from the forebrain vesicle

- slit-like cleft between the two thalami

- communicates anteriorly with the lateral ventricles through the interventricular foramina (foramina of Monro) posteriorly with the fourth ventricle through cerebral aqueduct

- has anterior, posterior, lateral, superior, and inferior walls and lined with ependyma

Anterior wall

- Formed by a thin sheet of gray matter, lamina terminalis, across which runs the anterior commissure

- Anterior commisure

o Round bundle of nerve fibers situated anterior to the anterior columns of the fornix ---they connect the right and left temporal lobes

Posterior wall

- Formed by the opening into the cerebral aqueduct

- Superior to this opening is the small posterior commissure

- Superior to the commissure is the pineal recess—which projects into the stalk of the pineal body

- Superior to the pineal recess is the small habenular commissure

Lateral wall

- Formed by the medial surface of the thalamus superiorly and the hypothalamus inferiorly

- These two structures are separated by the hypothalamic sulcus

- Lateral wall is limited superiorly by the stria medullaris thalami

- Joined by the interthalamic connection

Superior wall or roof

- Formed by the a layer of ependyma that is continuous with the lining of ventricle

- Superior is a two-layered fold of pia mater called tela choroidea of the third ventricle

- Vascular tela choroidea projects projects downward on each side of the midline, invaginating the ependymal roof to form the choroids plexuses of the third ventricle

o Within tela choroidea lie the internal cerebral veins

- Superiorly the roof of the ventricle is relatd to the fornix and the corpus callosum

Inferior wall or roof

- formed by the optic chiasma, tuber cinereum, infundibulum, with its funnel-shaped recess, and the mammillary bodies

- Hypophysis is attached to the infundibulum

- Posterior to these structures lies the tegmentum of the cerebral peduncles

GENERAL APPEARANCE OF THE CEREBRAL HEMISPHERES

Cerebral Hemispheres

- largest part of the brain

- Separated by a deep midline sagittal fissure, the longitudinal cerebral fissure

o The fissure contains the sickle shaped fold of dura mater, the falx cerebri and the anterior cerebral arteries

- Corpus Callosum

o Connects the hemispheres across the midline

- Tentorium Cerebelli

o Second horizontal fold of dura mater

o separates the cerebral hemispheres from the cerebellum

- Folds or gyri

o Increase surface area of the cerebral cortex maximally

o Where the surface of each cerebral hemisphere is thrown

o Separated from each other by sulci or fissures

- Lobes

o Named accdng to the cranial bones under which they lie

- Boundaries used for the division of the cerebral hemisphere into frontal, parietal, temporal, and occipital lobes:

o Central and Parieto-occipital sulci

o Lateral and calcarine sulci

MAIN SULCI

Central Sulcus

- of great importance because gyrus that lies anterior to it contains motor cells that initiate movements of the opposite side of the body

- Posterior to it lies general sensory cortex that receives sensory information from the opposite side of the body

- Indents the superior medial border of the hemisphere about 0.4 inch (1 cm) behind the midpoint

- Runs downward and forward across lateral aspect of the hemisphere, and its lower end is separated from the posterior ramus of the lateral sulcus by a narrow bridge of cortex

- Only sulcus of any length on this surface of the hemisphere that indents superomedial border and lies between two parallel gyri

Lateral Sulcus

- Deep cleft found mainly on the inferior and lateral surfaces of the cerebral hemisphere

- It consists of a short stem that divides into three rami

- The stem arises in the inferior surface and on reaching the lateral surface divides into:

o Anterior horizontal ramus

o Anterior ascending ramus

o And continues as the posterior ramus

- Insula

o An area in cortex that lies at the bottom of the deep lateral sulcus

o Cannot be seen from the surface unless the lips of the sulcus are separated

Parieto-Occipital Sulcus

- Begins on superior medial margin of the hemisphere about 2 inches (5 cm) anterior to occipital pole

- Passes downward and anteriorly on the medial surface to meet the calcarine sulcus

Calcarine sulcus

- Found on the medial surface of the hemisphere

- Commences under the posterior end of the corpus callosum

- Arches upward and backward to reach the occipital lobe, where it stops

- In some brains, however it continues for a short distance onto the lateral surface of the hemisphere

- Joined at an acute angle by the parieto occipital sulcus about halfway along its length

Herbal Medicines

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Herbal Medicine

Herbal medicine is defined as the use of natural herbs from plants for the treatment or prevention of diseases, disorders and the promotion of good health.

The use of herbs has been gaining popularity this past few years in the Philippines and worldwide as more clinical proof emerges that validates many of the age-old alternative medicines used by Filipino folks that has been passed on from generation to generation.

10 Herbal Medicines in the Philippines

Approved by the Department of Health (DOH)

These is the list of the ten (10) medicinal plants that the Philippine Department of Health (DOH) through its "Traditional Health Program" have endorsed. All ten (10) herbs have been thoroughly tested and have been clinically proven to have medicinal value in the relief and treatment of various aliments:

1. Akapulko (Cassia Alata) - also known as "bayabas-bayabasan" and "ringworm bush" in English, this herbal medicine is used to treat ringworms and skin fungal infections.

2. Ampalaya (Momordica charantia) - known as "bitter gourd" or "bitter melon" in English, it most known as a treatment of diabetes (diabetes mellitus), for the non-insulin dependent patients.

3. Bawang (Allium Sativum) - popularly known as "garlic", it mainly reduces cholesterol in the blood and hence, helps control blood pressure.

4. Bayabas (Psidium Guajava) - "guava" in English. It is primarily used as an antiseptic, to disinfect wounds. Also, it can be used as a mouth wash to treat tooth decay and gum infection.

5. Lagundi (Vitex Negundo) - known in English as the "5-leaved chaste tree". It's main use is for the relief of coughs and asthma.

6. Niyog-niyogan (Quisqualis Indica) - is a vine known as "Chinese honey suckle". It is effective in the elimination of intestinal worms, particularly the Ascaris and Trichina. Only the dried matured seeds are medicinal -crack and ingest the dried seeds two hours after eating (5 to 7 seeds for children & 8 to 10 seeds for adults). If one dose does not eliminate the worms, wait a week before repeating the dose.

7. Sambong (Blumea Balsamifera)- English name: Blumea Camphora. A diuretic that helps in the excretion of urinary stones. It can also be used as an edema.

8. Tsaang Gubat (Ehretia Microphylla Lam.) - Prepared like tea, this herbal medicine is effective in treating intestinal motility and also used as a mouth wash since the leaves of this shrub has high fluoride content.

9. Ulasimang Bato (Peperomia Pellucida) - also known as "pansit-pansitan" it is effective in fighting arthritis and gout. The leaves can be eaten fresh (about a cupful) as salad or like tea. For the decoction, boil a cup of clean chopped leaves in 2 cups of water. Boil for 15 to 20 minutes. Strain, let cool and drink a cup after meals (3 times day).

10. Yerba Buena (Clinopodium Douglasii) - commonly known as Peppermint, this vine is used as an analgesic to relive body aches and pain. It can be taken internally as a decoction or externally by pounding the leaves and applied directly on the afflicted area.

Tips on Handling Medicinal Plants / Herbs:

● If possible, buy herbs that are grown organically - without pesticides.

● Medicinal parts of plants are best harvested on sunny mornings. Avoid picking leaves, fruits or nuts during and after heavy rainfall.

● Leaves, fruits, flowers or nuts must be mature before harvesting. Less medicinal substances are found on young parts.

● After harvesting, if drying is required, it is advisable to dry the plant parts either in the oven or air-dried on screens above ground and never on concrete floors.

● Store plant parts in sealed plastic bags or brown bottles in a cool dry place without sunlight preferably with a moisture absorbent material like charcoal. Leaves and other plant parts that are prepared properly, well-dried and stored can be used up to six months.

Tips on Preparation for Intake of Herbal Medicines:

● Use only half the dosage prescribed for fresh parts like leaves when using dried parts.

● Do not use stainless steel utensils when boiling decoctions. Only use earthen, enameled, glass or alike utensils.

● As a rule of thumb, when boiling leaves and other plant parts, do not cover the pot, and boil in low flame.

● Decoctions loose potency after some time. Dispose of decoctions after one day. To keep fresh during the day, keep lukewarm in a flask or thermos.

● Always consult with a doctor if symptoms persist or if any sign of allergic reaction develops.

Emergency Drugs

2009-11-09T06:03:00.000-08:00

Medicines

Item name, Package, Quantity per kit

1 Furosemide 40 mg Tablets 30000

2 Methyl dopa 250 mg Ampoule 1 500

3 Hydralazine 25 mg injection Ampoule 1 000

4 Cimetidine 200 mg injection Ampoule 2 000

5 Promethazine 25mg/ml 2ml Ampoule 2 000

6 Morphine 50 mg/ml Ampoule 2 000

7 Pethidine 50 mg/ml Ampoule 10 000

8 Pentazocine 50 mg injection Ampoule 10 000

9 Chlorpromazine 25mg/ml Ampoule 1 000

10 Phenobarbitone 200 mg Ampoule 2 000

11 Amoxicillin + Ampicillin 500mg Cap 100 000

12 Cloxacillin 500mg Ampoule 10 000

13 Chloramphenicol 250mg, 1g Vial 10 000

14 Dextrose 5% IV sol. in saline 1L Bags 10 000

15 Atropine 1% eye drops Bot 5 000

16 Lignocaine 1-2% Vial 3 000

17 Lignocaine 5% spinal Vial 1 000

18 Neostigmine 2.5mg Ampoule 20 000

19 Suxamethonium 50 or 100 mg/ml Ampoule

Common drugs used in the Emergency Room

By Henry Feldman, ‘2001

(Edited by Lewis Nelson, MD)

Routes of administration

Intravenous administration is when the drug is given in liquid form directly into a vein. This is often

done by placing a venous catheter to allow easy administration.

Direct injection into the muscle. Often a painful mode of administration, and provides a slow route

of absorption.

By mouth (Per Orum). Typically intermediate between IM and IV in speed of absorption. (is this

true?)

Rectal administration (Per Rectum). The rectum is actually a very quick method of drug

administration as the rectum is highly vascular. This route is often used in children.

Certain drugs can be given down an endotracheal tube. The drugs are given at 2-2.5 times normal

IV dose. Drugs are followed with a saline bolus of ~10ml. The acronym for drugs that can go down

an ET tube is ALONE:

• A – Atropine

• L – Lidocaine

• O – Oxygen

• N – Naloxone (Narcan)

• E – Epinephrine

Drug List

Lidocaine

Lidocaine has 2 uses: It is a local anesthetic when injected subcutaneously (and it can be used

for a nerve block). It is also an antidysrhythmic drug when injected IV (used to treat cardiac

dysrhythmias). Anesthetic preparations come in 2 forms: with and without epinephrine. The

epinephrine is added to reduce absorption and prolong the effect. A classic question by the

resident/attending is: What is the toxic dose when used as a local anesthetic (Answer: 5mg/kg for

lidocaine without epi, and 7mg/kg with epi.)

Epinephrine

Epinephrine is a natural substance produced by the adrenal gland (a.k.a. adrenaline).

Epinephrine is used in emergencies to stimulate the heart or to dilate the bronchial tree. Its use is

limited by cardiac side effects. It is also mixed with lidocaine to prolong lidocaine’s effect and to

control bleeding.

Furosemide (Lasix)

Lasix is a diuretic, which is given IV or PO, which causes the patient to produce more urine. This

is often given to reduce the fluid overload in patients with congestive heart failure (a.k.a. CHF) or

hypertension.

Diazepam (Valium)

Diazepam is a benzodiazepine that is used both as a powerful sedative and as an anticonvulsant

for patients with seizures. You will see it used for alcohol withdrawal, cocaine toxicity,

and status epilepticus (i.e. uncontrolled seizures). Diazepam may produce respiratory depression.

Midazolam (Versed)

Versed is a very powerful short acting benzodiazepine type of sedative and is used to sedate

patients for painful procedures. Excessive dosing may produce respiration depression (when

given i.v.) or coma.

Haloperidol (Haldol)

Haldol is a antipsychotic with powerful sedative properties. It is often used for patients who are

acting in a psychotic manner. It should not be used to treat alcohol withdrawal or cocaince toxicity.

In sufficient quantities it will render the patient unconscious.

Succinylcholine

Often called “sux” (pronounced sucks), it is a paralytic, resulting in total muscular paralysis. It will

most often be used for “rapid-sequence-intubation” to make tracheal intubation easier and to

allow the patient to be mechanically ventilated. It has no analgesic properities and paralyzed

patients see, hear and feel everything - like a zombie! - thus it is never used without sedation.

Atropine

Atropine is used for several purposes, including inducing the heart to beat faster (i.e.

chronotropy) as well as an antidote for certain organophosphate poisonings. It is sometimes

used as a drug for patients with severe asthma. It can also be dripped into the eyes to produce

dilation of the pupil (although this is a different formulation). Can also be used to dry up respiratory

secretions during procedures.

Heparin

Heparin is an anticoagulant used to prevent blood from clotting. It is used in patients suspected

of having a myocardial infarction and to prep the syringe for an arterial-blood-gas for the same

reason.

Valproic Acid

Valproic Acid is used as an anticonvulsant medication. It is not typically used in the emergency

treatment of seizures, but toxicity can often be seen with seizure patients who have taken too

much.

Phenobarbital

Phenobarbital is a barbiturate which is used either as a sedative and/or anticonvulsant

medication.

Pentobarbital

Similar to phenobarbital but much faster acting and with a duration of effect. It is used as an

anticonvulsant medication and to treat severe alcohol withdrawal. Often used in a continuous

drip for patients who continue to seize.

Methylprednisolone (Solumedrol)

Solu-medrol is a long acting corticosteroid. It is often used to prevent the recurrence of

anaphylaxis after the epinephrine has worn off and for patients with asthma. It has a half-life of

around 6 hours.

Albuterol (Proventil)

Albuterol is a bronchodilator, used in a nebulizer for asthma patients. Typically a drop (0.5 mg)

of albuterol is suspended in saline and nebulized with oxygen. Often referred to as “how many

nebs the patient got”.

Ampicillin/Sulbactam (Unasyn)

This is an antibiotic (ampicillin) with the second compound added to prevent bacterial ßlactamases

from working (which interfere with penicillins). This overcomes the antibiotic resistance

acquired by many bacteria.

Flouroscein

This is a fluorescent dye used to stain the cornea to look for scratches or ulcers. Scratches and

ulcers will selectively retain the dye, making them glow under the cobalt-blue light of an

opthalmoscope.

Ketorolac (Toradol)

Ketorolac is a powerful NSAID, used for severe headaches, musculo-skeletal pain, kidney

stones and inflammation.

Morphine Sulfate

Morphine is a powerful opiate (derived from opium and similar to heroin) that is used as a pain killer

(i.e. analgesic). However, as a side effect it can suppress respirations.

Naloxone (Narcan)

Narcan is the antidote to opioids such as heroin or morphine. It is very rapidly acting and

competes with the opioid for the opioid receptor. Be careful when administering this drug, as it

may cause withdrawal in opioid tolerant patients.

Prednisone

Prednisone is a corticosteroid that is given for asthma and as an anti-inflammatory. A side effect

of prolonged use is Cushing’s syndrome and often you may see tremors.

Rocuronium

Often called “rock”, it is a paralytic. Administration produces total muscular paralysis. It is most

often used for “rapid-sequence-intubation” to make tracheal intubation easier and to allow the

patient to be mechanically ventilated. It has no analgesic properities and paralyzed patients see,

hear and feel everything and should never used without sedation.

Pilocarpine

Pilocarpine is dripped into the eyes to produce constriction of the pupil in patients with glaucoma.

Dopamine

Dopamine is a mild pressor agent, which is administered IV to produce vasoconstriction and raise a

patient’s blood presure.

Phenytoin (Dilantin)

Dilantin is an anticonvulsant. As a side effect, when administered too fast, it can induce

hypotension.

N-Acetylcysteine (Mucomyst)

Mucomyst is given in cases of acetaminophen toxicity (e.g. Tylenol).

tPA

Tissue plasminogen activator is a thrombolytic agent, used to lyse blood clots in patients with

myocardial infarction (a.k.a. heart attacks), non-hemorrhagic CVA’s (a.k.a. strokes) and PE’s (a.k.a.

pulmonary emboli). Thrombolytics can cause hemorrhage and should be used with care.

Streptokinase

Streptokinase is a thrombolytic (note: discovered here at NYU) made by Streptococcus bacteria

which dissolves clots, similar to tPA (although through a different mechanism)

Diltiazem(Cardizem)

Diltiazem is a calcium channel blocker used to slow the heart down in patients with certain

types of tachycardias such as atrial fibrillation.

Metoprolol

Metoprolol is a beta-blocker which is used to slow down the heart and lower blood-pressure.

These drugs are not typically used in asthmatics, as they can induce bronchoconstriction.

Atenolol

Atenolol is a beta-blocker similar to metoprolol.

Adenosine

Adenosine (the A of ATP fame) is used as an antidysrhythmic to break certain cardiac

dysrhythmias; it is often used in patients with supraventricular tachycardia. The half life of the drug

is only a few seconds, and can often induce non-pathologic asystole (flat line on an EKG) for a few

seconds.

Digoxin

Digoxin (a derivative of the Foxglove plant) is a cardiac drug used to slow conduction through

the heart, especially in cases of atrial-fibrillation. As a side effect it can produce various

dysrhythmias including ventricular fibrillation and aystole.

Metronidazole (Flagyl)

Flagyl is an antibiotic used against anaerobic bacteria and certain parasites. As a side effect

patients can become violently ill to their stomachs from consuming alcohol with Flagyl (similar to

Antabuse)

Vancomycin

Vancomycin is the “last ditch” antibiotic, used for highly resistant bacteria. It is fairly toxic to the

patient, and often is a hobson’s choice to administer to a septic, shocky patient.

Trimethoprim/sulfamethoxazole (Bactrim)

Bactrim is a “sulfa” class antibiotic and is often used in urinary tract infections.

Ketamine

A sedative often used in conjuction with other sedatives (such as midazolam or diazepam).

Pepcid

Pepcid is a systemic antacid (H2 blocker) which takes 30-45 minutes to take effect, but lasts for

several hours. Similar to ranitidine (Zantac) and cimetidine (Tagamet).

NS stands for Normal Saline, which is 0.9% Sodium Chloride, and is the usual fluid given to a

patient who needs fluid due to dehydration. It is approximately isotonic.

LR stands for Lactated Ringers, which is Normal Saline with other electrolytes. Due to the

presence of the other electrolytes, there is a limit to how much can be administered within a

specific period of time.

D5, D10, D25 and D50

The D stands for Dextrose, which is a stable form of glucose. This solution is given IV to give

the patient glucose. This is never given IM, as high concentrations of glucose cause tissue death

outside the vasculature.

Other useful terms

Once per Day

BID

Twice per day

TID

Three times per day

QID

Four times per day

QHS

At the hour of sleep

NPO

Nothing by mouth