Download Endocrine System Outline

Endocrine System Outline
II. Endocrine System
A. This system contains all of the Endocrine glands that make hormones.
B. Hormone - A hormone is a chemical messenger carried in the bloodstream. For example,
the adrenal gland makes Aldosterone which travels in the bloodstream to the kidneys and brings
the message to the nephron to reabsorb sodium. Not all cells in the body respond to the
hormones circulating in the bloodstream. Only cells with lock and key matching receptors to
the hormone will respond to the hormone. Those cells with matching receptors are called target
cells.
C. Pituitary Gland
1. Master gland - Certainly one of the most important endocrine glands in the body,
the pituitary does more to regulate body processes and other glands than does any
other endocrine gland. It is located just beneath the brain (specifically, the
hypothalamus).
2. Growth hormone - This hormone results in growth. Lack of enough GH during
childhood results in dwarfism.
3. Prolactin - "Lact-" means milk. When released, this hormone stimulates milk
production from the mammary glands.
4. TSH (Thyroid Stimulating Hormone) - As the name implies, this hormone
stimulates the thyroid gland.
5. ACTH (Adrenocorticotropic Hormone) - This hormone stimulates the adrenal
gland.
6. FSH & LH (Follicle Stimulating Hormone, Luteinizing Hormone) - These
reproductive hormones will be discussed under the Reproductive System.
7. ADH (Antidiuretic Hormone) - Although this hormone is actually made by the
hypothalamus of the brain, it is secreted from the pituitary gland. We studied it
under Excretory System, where we learned that it causes water reabsorption in the
kidneys.
8. Oxytocin - This hormone causes the uterus to contract during childbirth. It is
also made in the hypothalamus, but released from the pituitary gland.
D. Thyroid gland
1. Location - This paired gland is located in the neck region.
2. Thyroid hormone - The thyroid gland makes Thyroid Hormone. Iodine is
needed to make this hormone. Salt is iodized in the U.S., and thus iodine is seldom
deficient. Seafood is also a source of iodine. Thyroid hormone regulates the rate of
metabolism in the body.
E. Adrenal Gland
1. Location - The adrenal glands are small glands located just above the kidneys.
2. Medulla - The inner portion of the adrenal gland is the adrenal medulla. Here,
some of your "Fight or Flight" hormones are made. They are released in response
to an angry or fearful situation and exaggerate the fight or flight response.
a. Epinephrine (Adrenaline)
b. Norepinephrine
3. Cortex - The outer portion of the adrenal gland is the adrenal cortex. Several
hormones are made in this region, including:
a. Cortisol - A hormone that causes the body to conserve and store
energy (glucose), is anti-inflammatory, and suppresses the immune
response.
b. Aldosterone - This hormone results in sodium reabsorption from the
kidneys to the bloodstream.
F. Sex organs are certainly endocrine glands, but will be discussed later.
G. Pancreas
1. Location - As you recall from studying the pancreas as a digestive organ, it is
located just below the stomach.
2. Insulin - Insulin is made by the endocrine portion of the pancreas. Its role is to
take glucose out of the bloodstream and allow it to enter body cells, such as brain
cells. Thus, it lowers blood glucose.
3. Diabetes Mellitus - There are three types of Diabetes Mellitus. One is associated
with pregnancy; Type I is considered the Juvenile Onset Diabetes; and Type II is
considered the Adult Onset Diabetes with a heavy hereditary component. Type I
Diabetes is due to damage of the endocrine portion of the pancreas, resulting in no,
or too little, insulin being made. As a result, glucose stays in the bloodstream and
does not enter the cells. In fact, so much glucose stays in the bloodstream, that it
spills into the urine. Treatment for this type of Diabetes includes diet regulation,
blood glucose monitoring, and daily insulin shots.