Endocrine System 2

Endocrine System 2

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Endocrine System 2...

Endocrine System 2:

What exactly is the endocrine system? Well let's start by saying that this system is made up of any organ or gland that produces a secretion directly into the blood stream. Endocrine glands are also called ductless glands and glands of internal secretions. The hormones are directly excreted into the capillaries and circulate in the blood throughout the body.

The secretions are then transported to all areas of the body where they have a special influence on certain organs. There organs are called target organs or target tissues.

As some of you may be aware the nervous system regulates the body by means of nerve impulses which are very fast. The endocrine system is the other body system that regulates our body activities through a slower means of communication called hormones.

Chemical messengers from the endocrine system help regulate body activities. Their effect is of a longer duration and is more generalized than that of the nervous system.

FLASHBACK....FLASHBACK.....FLASHBACK

Remember the lessons on levels of organization within the body? Cells working together in a similar function are called tissues. Tissues working together in a similar function are called organs and organs working together in a similar function are called systems. Remember this not too long ago??

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There are two major categories of glands in the body- exocrine and endocrine.

EXOCRINE- have ducts that carry their secretions to the surface. These have a variety of functions and include the sweat, sebaceous, mammary glands and the glands that secrete digestive enzymes such as the salivary gland.

ENDOCRINE- do not have ducts to carry their products to a surface. The secretions of the endocrine glands are called hormones.

Some hormones have one target organ while others may have many target organs. In general, the endocrine system and it's hormones help to regulate growth, the use of foods to produce energy, resistance to stress, the pH of body fluids and fluid balance and reproduction. As you can see from this list, the endocrine system plays a very big part is maintaining homeostasis.

MECHANISM OF HORMONE ACTION

Hormones are carried by the blood throughout the entire body, yet they only affect certain cells. The specific cells that respond to a given hormone have receptor sites for that hormone.

This is a sort of lock and key mechanism. If the key fits the lock then the door will open. If the hormone fits the receptor site then their will be an effect. If the hormone and the receptor site do not match there will be no reaction.

All the cells that make up the receptor sites for a given hormone make up the target tissue or the target organ.

In some cases, the target tissue is localized in a single gland or organ. In other cases, the target tissue is diffuse or scattered throughout the body so that many areas are affected.

Hormones bring about their effects on target cells by modifying or changing cellular activity.

Receptor sites may be located either on the surface of the cell membrane or in the interior of the cell. Protein hormones react with the receptors on the surface of the cell, and the sequence of events that results in hormone reaction is relatively rapid. Steroid hormones typically react with receptor sites inside of the cell. Because this method of action actually involves synthesis of proteins, it is relatively slow.

Protein hormones are unable to diffuse through the cell membrane and react with the receptor sites on the surface of the cell. The hormone-receptor reaction on the cell membrane activates an enzyme within the cell membrane.

Within the cell a chain of events takes place that activates enzymes within the cytoplasm that alters the cellular activity. The protein hormone which reacts at the cell membrane is called the first messenger. The chemical chain of events which brings about the action attributed to the hormone is called the second messenger. This type of action is relatively rapid because the precursors are always present and they just need to be activated in some way.

Steroids diffuse through the cell membrane and react with receptors inside the cell. The hormone receptor complex that forms enters the nucleus, where it has direct effect on the specific genes within the DNA. The proteins that are formed in the RNA and the DNA represent the cell's response to the hormone. This method of hormone action is relatively slow because the proteins actually have to be built and constructed to specifications rather than just be activated.

HORMONAL CONTROL

Hormones are very potent substances, therefore very small amounts of a hormone may have a significant effect on the metabolic process.

Because of their potency, hormone secretion must be regulated within very narrow limits in order to maintain homeostasis in the body.

The cells of endocrine glands respond to changes in the blood, or perhaps to other hormones in the blood. These stimuli are the information they use to increase or decrease secretion of their own hormones.

The secretion of the hormones operates on a negative feedback system or under the control of the nervous system. In negative feedback there is a drop in the level of the hormone, which triggers a response to increase the amount of hormone in the blood. A negative feedback system causes the reversal of increases and decreases in body conditions in order to maintain a state of stability or homeostasis.

Some endocrine glands secrete hormones in response to other hormones. The hormones that cause secretion of other hormones are called tropic hormones.

A third method of regulating hormone secretion is by direct nervous stimulation. A nerve stimulus causes Gland A to secrete it's hormone.

So......I guess that it is safe to say that there are three actions of hormones:

regulation by a negative feedback mechanism

action controlled by other hormones

other are affected by nerve stimulation

You can bet that you will see that on a quiz somewhere in the near future!!!

While we're at it let's talk about releasing versus inhibitory hormones. These actions do exactly as you would suspect. These hormones are secreted in response to nerve stimulation from the hypothalamus. The releasing hormone is very specific; it only stimulates one hormone secretion. Therefore if the releasing hormone for a specific hormone such as TSH, the rest of the hormones will not be released when there is no need for their action. WOW...this is a good thing. I was starting to get worried for a minute. But, let's not get over excited; you knew there would have to be another piece of this story. The releasing hormone which may also inhibit the action of a gland and it's secretion. such as the growth hormone.

HORMONE STRUCTURE

With respect to their chemical structure, hormones may be classified into three groups.

1. Amines- these simple hormones are variations of the amino acid tyrosine. This group includes thyroxine from the thyroid gland and epinephrine and norepinephrine from the adrenal medulla.

2. Proteins- these hormones are chains of amino acids. Insulin from the pancreas, growth hormone from the anterior pituitary, and calcitonin from the thyroid are all proteins. Short chains of amino acids are called peptides. Antidiuretic hormones and oxytocin, synthesized by the hypothalamus, are peptide hormones.

3. Steroids- cholesterol is the precursor for the steroid hormones, which include cortisol and aldosterone from the adrenal cortex, estrogen and progesterone from the ovaries and testosterone from the testes.

ENDOCRINE GLANDS AND THEIR HORMONES

Even though the endocrine glands are scattered throughout the body, they have numerous interrelationships and similar mechanisms of action. They are considered one system however.

PITUITARY GLAND

The pituitary gland or also called the hypothysis is a small gland that hangs by a short stalk from the hypothalamus. It is surrounded by bone as it rests in the sella turcica or a depression in the sphenoid bone of the skull.

There are 2 distinct regions in this gland. The anterior portion called the adenohypophysis and the posterior portion which is also an extension of the brain called the neurohyopohysis. (made up of neurons and neuroglia)

Despite it's size the pituitary regulates many body functions. Just as there are two distinct regions or lobes, there are separate regulating mechanisms that influence the secretions of the two parts.

HORMONES OF THE ANTERIOR PORTION OF THE PITUITARY OR THE ADENOHYPOPHYSIS

GROWTH HORMONE : also may be called somatotropin. This hormone is a protein that stimulates growth of bones, muscles and other organs. This hormone drastically affects the appearance of an individual because it affects height.

If there is too little of this hormone a person may become a pituitary dwarf of normal appearance but of small stature.

An excess of the hormone in a child results in exaggerated bone growth, and the individual becomes exceptionally tall or a giant. After ossification or bone formation is complete and an increase in bone length is no longer possible, excess growth hormone causes an enlargement in the diameter of the bones resulting in a condition called acromegaly where the bones of the hands and face become abnormally large.

You may be wondering if growth hormone is secreted in adults. The answer is yes. Amazing as our body is we find all sorts of additional duties for our body parts. GH also helps with the building of proteins within our bodies which we all need even if we have reached our maximum growth level. Also GH stimulates the release of fat from adipose tissue which helps us with energy production when we go for extended periods without eating.

THYROID STIMULATING HORMONE: also called TSH or thyrotropin, causes the thyroid to secrete thyroid hormone. The target organ for TSH is the thyroid. The thyroid regulates metabolism. When there is hypersecretion of TSH the thyroid gland enlarges and secretes too much thyroid hormone. When there is hyposecretion of TSH there is an atrophy of the gland and too little secretion of the hormone. We will talk about the thyroid gland in greater detail as we go on further.

ADRENOCORTICOTROPIC HORMONE: also known as ACTH reacts with the receptor sites in the cortex of the adrenal gland to stimulate the secretion of cortical hormones, particularly cortisol. This hormone is produced in any type of physiological stress situation such as injury or hypoglycemia or exercise.

PROLACTIN: or lactogenic hormone is just as it name reflects. This hormone promotes glandular tissue development during pregnancy which means simply that the breasts enlarge and it also stimulates milk production after the birth of an infant. If the mother continues to breast feed the prolactin levels remain high. This hormone is responsible for the production of milk. A hormone from the posterior pituitary combined with nerve stimulation is responsible for the ejection of milk from the breast.

Hyposecretion of prolactin presents no problem except in women who choose to breastfeed their babies.

Hypersecretion is more common and is usually the result of pituitary tumors. This causes inappropriate lactation and lack of menstruation in females. In males, it results in impotence.

FOLLICLE STIMULATING HORMONE: or FSH has it's effects on the ovaries or testes. FSH is named for one of it's functions in women. This hormone stimulates the eggs in the ovaries and the sperm in the testes. In addition, it stimulates estrogen production in the female. Basically, what we are trying to get across is that in the female ovary there are follicles that FSH stimulates the egg production in cycles of approximately every 28 days.

LUETINIZING HORMONE: or LH is responsible for ovulation or the release of a mature ovum from the ovarian follicle. LH then stimulates that follicle to develop into a corpus luteum. The corpus luteum will be discussed in our studies on the female reproductive system but until then let's just say that it is the mature or ripened follicle that remains in the ovary awaiting fertilization.

INTERSTITIAL CELL STIMULATING HORMONE: or ICSH is stimulated by LH to produce testosterone in the testes.

MELANOCYTE STIMULATING HORMONE: or MSH which influences the melanocytes of the skin to produce melanin. Melanin reacts to sunlight and will cause the skin to darken.

HORMONES OF THE POSTERIOR LOBE OF THE PITUITARY OR THE NEUROHYPOPHYSIS

ANTI-DIURETIC HORMONE: promotes the reabsorption of water through the kidney tubules, with the result of less water lost than urine. This mechanism conserves water for the body.

Hyposecretion of ADH causes excessive water loss in the urine resulting in large amounts of dilute urine. This condition is also known as diabetes insipidus.

Hypersecretion of ADH causes blood vessels to constrict, which increases blood pressure. For this reason, ADH is sometimes called vasopressin.

Certain drugs, called diuretics, counteract the effects of ADH and result in fluid loss. These drugs are sometimes prescribed for patients with patients with high blood pressure or those with edema due to congestive heart failure because the drugs have the effect of removing fluid from the body.

OXYTOCIN: causes contraction of the smooth muscle in the wall of the uterus. It also stimulates the ejection of milk from the lactating breast. A commercial preparation of this hormone, called Pitocin, is sometimes used to induce labor by stimulating the smooth muscle contraction of the uterus. One of the many reasons that healthcare providers encourage breastfeeding is due to the immediate stimulation of the postpartum uterus to contract when nursing. This helps the uterus return to it's prenatal state. Oxytocin or a synthetic version of this hormone also may be used to hasten the delivery of the placenta, control bleeding after delivery and to stimulate milk ejection.

THYROID GLAND

The thyroid gland is a very vascular gland that is located in the neck. It is estimates that 4-5 liters of blood pass through the gland every hour. It also consists of 2 lobes; one on each side of the trachea just below the larynx. The two lobes are connected by a narrow band of tissue called the isthmus. The structural units of the thyroid gland are thyroid follicles. The thyroid gland secretes three hormones; thyroxine (T4), triiodothyronine (T3) and calcitonin. About 95% of the active thyroid hormone is thyroxine. Both of these hormones require iodine for their synthesis. The thyroid hormone secretion is regulated by a negative feedback system that involves the amount of circulating hormones.

If there is an iodine deficiency, the thyroid cannot make sufficient hormone. This stimulates the anterior pituitary to secrete TSH, which causes the thyroid gland to increase in size in a useless attempt to produce more hormone. AHHH...but then again it cannot produce more hormone because it does not have the necessary raw material or iodine to do this.

A simple goiter is an enlarged thyroid gland resulting from a deficiency of iodine in the diet.

Thyroxine controls the rate of metabolism, heat production and oxidation of most cells. To summarize, the functions of thyroxine are as follows:

controlling the rate of metabolism; how cells utilize oxygen to produce heat and energy.

is a diuretic and promotes water loss through urine

promotes protein synthesis or building and thus helps with tissue growth

stimulates the breakdown of liver glycogen.

stimulates the cellular breakdown of glucose

CALCITONIN: controls the calcium concentration in the body by maintaining a proper calcium level in the bloodstream. Calcium is an essential body mineral. Approximately 99% of the calcium in the body is stored in the bones. The rest is located in the blood and tissue fluids. Calcium is necessary for blood clotting, holding cells together and neuromuscular functions. Calcitonin decreases the reabsorption of calcium and phosphate from the bones to the blood thereby lowering blood lowering blood levels of these minerals. This function of calcitonin helps maintain normal blood levels of these minerals while helping to maintain a strong bone matrix. It is believed that calcitonin exerts it's most important influence during the childhood years when the bones are growing at significant rates.

Hypercalcemia is when the blood levels of calcium are high. This triggers the stimulation of calcitonin and means that no more calcium will be removed from the bones until there is a real need for more calcium in the blood.

PARATHYROID GLANDS

Parathyroid glands are usually four in number are very tiny about the size of grains of rice. They are attached to the posterior surface of the thyroid gland and secrete the hormone, parathormone or PTH.

PARATHORMONE: or PTH is the most important regulator of blood calcium levels. It is secreted in response to low blood calcium levels and it's effect is to increase those levels. Parathormone increases the stimulation of the number and the size of specialized bone cells called osteoclasts. An osteoclast is a special cell that is involved in resorption of bony tissue.

Osteoclasts invade the bony tissue, digesting large amounts of the bony material containing calcium. As this process continues, calcium leaves the bone and is released into the bloodstream thus increasing the blood calcium level.

Now, you may be saying to yourself...earlier on we were linking calcium and phosporus together. Well we still are thinking along those lines. Bone calcium is bonded to phosphorus in a compound that is called calcium phosphate. So when calcium is released into the bloodstream, phosphorus is released along with it.

PTH and calcitonin have opposite or antagonistic effects to one another.

Hypoparathyroidism or insufficient secretion of PTH, leads to increased nerve excitability. The low blood calcium levels trigger spontaneous and continuous nerve impulses which trigger muscle contraction.

Your mind is racing if you have had the muscular system. Now, what exactly does the role of calcium have to do with muscle contraction or if you haven't had this system yet..you know that you have seen and heard for years all these athletes talking about milk and calcium and how important this is.

Well think of this.......... We know that we need calcium to help us provide the strong foundation for our bone growth. We also need to have calcium to help with muscle contraction. Muscle fibers are made from thin and thick fibers in order for them to intertwine and have smooth and fluid movement when contracting. Calcium is one of the chemicals that is involved in changing the way that the fibers intertwine and then ultimately allow for the muscle fibers to shorten and contract. There you see the connection now?????

Hyperparathyroidism or an excessive secretion of PTH leads to an increase in the osteoclast activity that removes calcium from the bones and excretes it into the bloodstream. This increase in calcium in the blood may lead to kidney stones or a buildup of mineral deposits that can be found in abnormal places. It may also lead to a bone disease called osteitis fibrosa cystica where the bone mass decreases, decalcification occurs, cyst like cavities appear in the bone and spontaneous fractures result.

THYMUS GLAND

The thymus gland is both and endocrine gland and a lymphatic organ. Fairly large during childhood, it begins to atrophy and disappear in puberty and is essentially nonfunctional into early adulthood. Recent research has discovered that this gland secretes a large number of hormones. These hormones help to stimulate the lymphoid cells that are responsible for the production of antibodies against certain diseases.

THYMOSIN: enhances the development of T-cell lymphocytes which help to protect the body from foreign invaders. If an infant is born without a thymus gland, the immune system does not properly develop and the body is highly susceptible to infections.

OK..OK... so you have now guessed the truth. I like you to know little factoid about certain subjects so you can link things together. Well here it goes. I know a student in our program who frequently does independent research. Along her travels she came up with a very interesting factoid about the thymus gland and it's relationship to tumor formation.

Did you ever wonder why with advancing age we are constantly on the lookout for tumors or irregularities in our bodies??? Well, we know that the thymus produces special cells that help us fight off foreign invaders. The majority of our cells are produced while the thymus is functioning. These special cells have a life span of about 60 years within our bodies. So.. as our age advances are lymphocytes decrease naturally and now we have a non-functioning thymus so therefore we cannot replace the loss. Interesting factoid.

ADRENAL OR SUPRARENAL GLANDS

These glands are paired with our kidneys. They are located near the upper portion of each kidney and are embedded in the adipose capsule or fatty portion of the exterior kidney. Each gland is divided into the an inner and an outer region. The inner region is called the adrenal medulla and the outer region which is called the adrenal cortex. The adrenal cortex is essential to life but the adrenal medulla may be removed with no life threatening consequences.

ADRENAL MEDULLA

EPINEPHRINE: also known as adrenalin is a cardiac stimulator. It functions by bringing about a release of more glucose from stored glycogen for muscle activity; and increasing the force and the rate of the heartbeat. This chemical activity increases cardiac output and venous return, and raises the systolic blood pressure. It also dilates the bronchioles, decreases peristalsis and increases the rate of cell respiration.

Very often, as a Medical Assistant you will be asked to inject “epi” or epinephrine to an asthmatic patient who may be in crisis. In this event it is very important to take an apical pulse for a full minute to get an accurate heart rate. Very often the Provider will ask you to repeat that pulse check in 5 minutes to see if there has been a significant change in the rate or rhythm.

Now...here is little extra credit assignment. If your feeling so inclined, why don't you write me paper (less than 150 words) on why it would by important to check the apical pulse and what does the rate have to do with the rhythm.

NOREPINEPHRINE: is secreted in small amounts and it's most significant function is to cause vasoconstriction in the skin, viscera, and skeletal muscles to raise blood pressure.

Both norepinephrine and epinephrine are secreted in stressful situations and help the body prepare for “flight or fight”. Remember this phenomenon. These two hormones have effects similar to the sympathetic nervous system.

Now, you know I am obliged to just briefly discuss the “flight or fight” response. The sympathetic division of the nervous system is concerned primarily with the preparation of the body for stressful or emergency situations. Meaning that it stimulates the responses needed to meet the emergency while inhibiting the visceral or organ activities that can be delayed momentarily.

For example, during an emergency, the sympathetic nervous system increases the breathing rate, heart rate, and blood flow to the skeletal muscles. At the same time, it decreases activity in the digestive tract because this function is not needed during an emergency.

There now that we have cleared that up, we can move on.

HORMONES OF THE ADRENAL CORTEX

All hormones from the adrenal cortex are steroids. Three types of steroids to be exact:

mineralcorticoids- regulate blood volume and the concentration of mineral electrolytes in the blood.

glucocorticoids- help to regulate nutrient levels in the blood, the overall effect is to increase blood glucose levels.

sex hormones or gonadocorticoids- sex hormones from the adrenal cortex have minimal effect compared with the hormones from the ovaries and testes.

ALDOSTERONE: is a mineralcorticoid and is the most abundant of it's type. It primarily affects the kidneys and in general its effect is to conserve sodium ions and water in the body and to eliminate potassium ions.

Sodium and potassium levels are important in maintaining blood pressure, nerve impulse conduction, and muscle contraction.

A tumor of the adrenal cortex may lead to hypersecretion of mineralcorticoids. If this results in excessive potassium depletion, neurons and muscle fibers become less responsive to stimuli. Symptoms of this condition include paralysis, muscle weakness and cramps.

CORTISOL: is also called hydrocortisone and is the principal glucocorticoid. This hormone increases cellular utilization of proteins and fats as energy sources, thus conserving glucose. It also stimulates the liver cells to produce glucose from amino acids and fats. These actions help to maintain appropriate blood glucose levels between meals. In times of prolonged stress, cortisol is secreted in larger amounts than normal to respond to the stress. Cortisol is secreted in any type of physiological stress, disease, hemorrhage, hunger, fear or anger and exercise.

Cortisol also helps to reduce the inflammatory response. For this reason, it is used clinically to reduce the inflammation in certain types of allergic reactions, bursitis, arthritis, infection and in some types of cancer. Although inflammation is an essential first step in tissue repair, it can become a viscious cycle of damage..inflammation...damage..inflammation etc. Normal cortisol secretion seems to limit the inflammatory process to what is used for tissue repair and to prevent excessive tissue destruction. Too much cortisol, however, decreases the immune response, leaving the body susceptible to infection and significantly slowing the healing of damaged tissue.

GONADOCORTICOIDS: are grouped into the male hormones called androgens and the female hormones called estrogens. In females, the masculinization effect of androgen secretion may become evident after menopause, when estrogen levels from the ovaries decrease.

Tumors that result in hypersecretion of these hormones may have a dramatic effect on prepubertal boys and girls. There is a rapid onset of puberty and sex drives in males. Females may develop the masculine distribution of body hair, including a beard,and the clitoris becomes enlarged like a penis.

Hyposecretion of the adrenal cortex leads to a condition called Addison's disease. This results in low blood glucose levels, low blood sodium and high blood potassium, dehydration and increased pigmentation of the skin. If left untreated can result in death in just a few days.

Hypersecretion of the adrenal cortex causes Cushing's syndrome. This is demonstrated by high blood glucose levels, edema and retention of sodium ions, and masculinization in females.

PANCREAS

The pancreas is located in the LUQ of the abdomen lying transversely on the posterior abdominal wall. The pancreas is a digestive organ as well as an endocrine gland. The endocrine portion of the pancreas consists of the pancreatic islets or islets of Langerhans, which secrete alpha cells which secrete glucagon and beta cells which secrete insulin. Both of these hormones have a role in regulating blood glucose levels.

GLUCAGON: The alpha cells in the pancreatic islets secrete glucagon in response to a low concentration of glucose in the blood or hypoglycemia. It does this by mobilizing glucose and fatty acids from their storage forms.

INSULIN: Beta cells in the pancreatic islets secrete insulin in response to a high concentration of glucose in the blood. The action of insulin is opposite or antagonistic to glucagon. It promotes utilization of glucose for energy. When the liver has stored all the glycogen possible, glucose is converted into adipose or fat tissue.

Hyposecretion of insulin may be caused by insufficient insulin secretion, insufficient receptor sites on the target cell membranes or defective receptor site cells that do not recognize insulin. These dysfunctions lead to diabetes mellitus, which is characterized by abnormally high blood glucose levels.

Secretion of insulin is stimulated by hyperglycemia or a high blood glucose level.

OVARIES

The ovaries are located in the pelvic cavity, one on each side of the uterus. The hormones produced by the ovaries are the steroids estrogen and progesterone.

These hormones contribute to the development and function of the female reproductive organs and sex characteristics.

ESTROGEN: At the onset of puberty, estrogen promotes:

the development of breast tissue

distribution of fat evidenced in the hips, legs, and breasts

maturation of reproductive organs such as the uterus and vagina (menstruation)

the closure of epiphyseal discs in long bones

PROGESTERONE: causes the uterine lining to thicken in preparation for pregnancy. This thickening of the endometrium allows for further growth of blood vessels which will eventually become a placenta. Progesterone also promotes the storage of glucogen.

TESTES

The testes are located in the scrotum which is a sac of skin that lies between the upper part of the thighs. The testes secrete two hormones called testosterone and inhibin.

TESTOSTERONE: production of testosterone begins during fetal development, continues for a short time after birth, nearly ceases during childhood, then resumes at puberty. This hormone is responsible for:

growth and development for the male reproductive system

increased skeletal and muscular growth

enlargement of the larynx accompanied by voice changes

growth and distribution of body hair

increased male sexual drive

closure of the epiphyseal discs of the long bones of the body

INHIBIN: is the stimulus for secretion is an increased level of testosterone. The interaction of inhibin, testosterone, and other hormones from the pituitary maintain spermatogenesis or the manufacturing of sperm.

PINEAL GLAND

The pineal gland also called the pineal body is a small cone shape structure that extends from the third ventricle of the brain. The pineal gland consists of portions of neurons and neuroglia with specialized cells. Theses pinealocytes secrete melatonin directly into the cerebrospinal fluid, which takes it directly into the bloodstream.

The subject of the pineal gland and melatonin in humans has been the subject of controversy for centuries. It appears that melatonin acts on the hypothalamus to inhibit releasing hormones for sex organ development.

Another function of melatonin involves the organization and regulation of circadian rhythms or our daily sleepiness/wakefulness cycle. The hormone also appears to have an impact in our hunger/satiety cycles, mood changes, and jet lag.

Melatonin production appears to be related to the amount of light that enters through the eye. People who work at night and sleep during the day have a reversed cycle of melatonin production. The high levels occur during the day while they are asleep and the low levels are at nigh when they are working and light is entering the eye.

OTHER HORMONES AND ASSOCIATED STRUCTURES

There are other organs that produce hormones that have only one or a few target organs. The stomach and the duodenum produce hormones that regulate aspects of digestion called gastrin and secretin.

The placenta is the pregnant female serves as temporary gland and it secretes human chorionic gonadotropin or HCG. The hormone that is measured either qualitatively or quantitatively to determine the presence or viability of a pregnancy.

PROSTAGLANDINS: are potent chemical regulators that are produced in minute amounts and are found widely distributed in cells throughout the body. They have an immediate, short term and localized effect.

Prostaglandins are known to be involved in inflammation, pain mechanisms, blood clotting, vasoconstriction and vasodilatation, contraction of the uterus, reproduction , secretion of digestive hormones, and nutrient metabolism.

SUMMARY

The hormones of the endocrine glands are involves in virtually all aspects of normal body functioning. As you have learned in this chapter there are many complicated and intriguing disorders of the endocrine system that may prove to have a wide reaching effect and many body systems.

Please write a 2-3 page report on any disorder of the Endocrine System.

Include the following:

Name of disorder

Etiology/cause, onset of symptoms

Clinical presentation of the disorder

Diagnostic tests that may be utilized in establishing a diagnosis

Treatment options

Patient education resources or teaching modules

ICD-9 code used for this disorder

How this relates to your role as a Medical Assistant

You must use common simple (laymen's) terms wherever possible in your report. Please type the report, double spaced, include a cover sheet and bibliography and do not forget to use your fellow students as resources should you not understand how to do any portion of this project. (ie. ICD-9 coding) Good Luck...this will count as one quiz grade in A & P.