Download Anatomy of the Endocrine System

Endocrinology Health Guide
The endocrine system is a complex collection of hormone-producing
glands that control basic body functions such as metabolism, growth
and sexual development. The amount of hormones produced by each
gland is carefully balanced. Too much or too little of a certain hormone
can have effects throughout the body and cause various endocrine
disorders. Many of the hormones produced by the endocrine glands
interact with each other to maintain balance.
The endocrine system consists of:
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pituitary gland - secretes hormones to stimulate the adrenals,
thyroid, pigment-producing skin cells and gonads (ovaries and
testes). Also secretes
a growth hormone, an antidiuretic hormone, prolactin (a hormone
which affects milk production after childbirth) and oxytocin (a
hormone which plays a role in childbirth).
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hypothalamus - secretes hormones that stimulate or suppress
the release of hormones in the pituitary gland.
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pancreas - secretes insulin and glucagon, which affect the
body's absorption of glucose, the body's main source of energy.
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adrenal cortex - secretes hydrocortisone, which affects
metabolism. Also secretes androgen hormone and aldosterone,
which affect blood pressure and saline balance.
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thyroid gland - secretes thyroxin, triiodothyronine and
calcitonin, which affect metabolism, body heat, and bone growth.
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parathyroid glands - secretes a parathyroid hormone, which
affects calcium levels in the blood.
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gonads - the male and female reproductive glands (testes and
ovaries). The testes secrete testosterone, which stimulate sperm
production and other male characteristics. The ovaries secrete
estrogen and progesterone, which affect many aspects of the
female body, including menstrual cycles and pregnancy.
The exocrine glands actually secrete their substances through ducts to
particular areas. Examples of exocrine glands include the salivary
glands and the sweat glands. The endocrine glands, on the other hand,
secrete the hormones they produce directly into the bloodstream. Most
endocrine glands are controlled by trophic (stimulating) hormones
secreted by the pituitary gland. The pituitary gland, in turn, is
controlled by hormones secreted by the hypothalamus in the brain.
Acromegaly
What is acromegaly?
Acromegaly is the Greek word for "extremities" and "enlargement."
When the pituitary gland produces excess growth hormones, this
results in excessive growth -- called acromegaly. The excessive growth
occurs first in the hands and feet, as soft tissue begins to swell.
Acromegaly affects mostly middle-aged adults. Untreated, the disease
can lead to severe illness and death.
What are the symptoms of acromegaly?
Symptoms of acromegaly vary depending on how long the patient has
had the disease. The following are the most common symptoms.
However, each individual may experience symptoms differently:
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swelling of the hands and feet
facial features become coarse as bones grow
body hair becomes coarse as the skin thickens and/or darkens
increased perspiration accompanied with body odor
protruding jaw
voice deepening
enlarged lip, nose, and tongue
thickened ribs (creating a barrel chest)
joint pain
degenerative arthritis
enlarged heart
enlargement of other organs
strange sensations and weakness in arms and legs
snoring
fatigue and weakness
headaches
loss of vision
irregular menstrual cycles in women
breast milk production in women
impotence in men
The symptoms of acromegaly may resemble other conditions or
medical problems. Consult a physician for diagnosis.
How is acromegaly diagnosed?
Due to the subtlety of the symptoms, acromegaly is often not
diagnosed until years later. In addition to a complete medical
history and medical examination, diagnostic procedures for
acromegaly may include:
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serial photos taken over the years to observe physical changes
in the patient
x-rays to detect bone thickening
blood tests to check the growth hormone level
Treatment for acromegaly:
Treatment of acromegaly depends on the cause of the disease. Ninety
percent of acromegaly cases are caused by benign tumors on the
pituitary gland. Because the tumor is compressing the pituitary gland,
the hormone production can be altered. Some other acromegaly cases
are caused by tumors of the pancreas, lungs, or adrenal glands.
The goal of treatment is to restore the pituitary gland to normal
function, producing normal levels of growth hormone. Specific
treatment for acromegaly will be determined by your physician based
on:
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your overall health and medical history
extent of the disease
your tolerance for specific medications, procedures, or therapies
expectations for the course of the disease
your opinion or preference
Treatment may include removal of the tumor, radiation therapy, and
injection
of a growth hormone blocking drug.
Left untreated, acromegaly can lead to diabetes mellitus and
hypertension.
The disease also increases a patient's risk for cardiovascular disease
and
colon polyps that may lead to cancer.
Diabetes Insipidus
FACT:
Though produced by the hypothalamus, the portion of the brain that stimulates
the pituitary gland, the antidiuretic hormone, is actually stored and released into
the blo ction of the antidiuretic hormone by the hypothalamus, the
portion of the brain that stimulates the pituitary gland. Normally, the
antidiuretic hormone controls the kidneys' output of urine. Diabetes
insipidus causes excessive thirst and excessive production of very
diluted urine.
Causes of diabetes insipidus:
Diabetes insipidus can be caused by several conditions, including:
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malfunctioning hypothalamus
malfunctioning pituitary gland
damage to hypothalamus or pituitary gland during surgery
brain injury
tumor
tuberculosis
blockage in the arteries leading to the brain
encephalitis
meningitis
sarcoidosis (a rare inflammation of the lymph nodes and other
tissues
throughout the body)
What are the symptoms of diabetes insipidus?
The following are the most common symptoms. However, each
individual may experience symptoms differently:
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excessive thirst
excessive urine production
dehydration
The symptoms of diabetes insipidus may resemble other conditions or
medical problems. Consult a physician for diagnosis.
How is diabetes insipidus diagnosed?
In addition to a complete medical history and medical examination,
diagnostic procedures for diabetes insipidus may include:
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urine tests
blood tests
water deprivation test (to observe if dehydration occurs)
Treatment of diabetes insipidus:
Treating diabetes insipidus depends on what is causing the disease.
Treating the cause usually treats the diabetes insipidus. Specific
treatment for diabetes insipidus will be determined by your physician
based on:
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your overall health and medical history
extent of the disease
your tolerance for specific medications, procedures, or therapies
expectations for the course of the disease
your opinion or preference
Treatment may i nclude modified antidiuretic hormone drugs or
drugs to stimulate the production of the antidiuretic hormone.
Anatomy of the Endocrine System
hypothalamus
What are hormones?
Hormones are chemical substances created by the body that control numerous
body functions. They actually act as "messengers" to coordinate functions of
various body parts. Most hormones are proteins consisting of amino acid chains.
Some hormones are steroids, fatty cholesterol-produced substances. Functions
controlled by hormones include:
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activities of entire organs
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growth and development
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reproduction
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sexual characteristics
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usage and storage of energy
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levels of fluid, salt and sugar in the blood
The hypothalamus is located in the brain, at the base of the optic
chiasm. It secretes hormones that stimulate or suppress the release of
hormones in the pituitary gland, in addition to controlling water
balance, sleep, temperature, appetite, and blood pressure.
pineal body
The pineal body is located below the corpus callosum, a part of the
brain. It produces the hormone melatonin.
pituitary
The pituitary gland is located at the base of the brain. No larger than a
pea, the gland controls many functions of the other endocrine glands.
thyroid and parathyroids
The thyroid gland and parathyroid glands are located in front of the
neck, below the larynx (voice box). The thyroid plays an important role
in the body's metabolism. Both the thyroid and parathyroid glands also
play a role in the regulation of the body's calcium balance.
thymus
The thymus is located in the upper part of the chest and produces Tlymphocytes (white blood cells that fight infections and destroy
abnormal cells).
adrenal gland
The pair of adrenal glands are located on top of both kidneys. Adrenal
glands work hand-in-hand with the hypothalamus and pituitary gland.
kidney
The pair of kidneys are located near the middle of the back, just below
the rib cage. The kidneys process the blood to sift out waste products
and extra water. This waste and extra water becomes urine, which is
stored in the bladder.
pancreas
The pancreas is located across the back of the abdomen, behind the
stomach. The pancreas plays a role in digestion, as well as hormone
production.
ovary
A woman's ovaries are located on both sides of the uterus, below the
opening of the fallopian tubes (tubes that extend from the uterus to
the ovaries). In addition to containing the egg cells necessary for
reproduction, the ovaries also produce estrogen and progesterone.
testis
A man's testes are located in a pouch that hangs suspended outside
the male body. The testes produce testosterone and sperm.