Anatomy of the Endocrine System
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-derived substances. Functions controlled by hormones include:
- activities of entire organs
- growth and development
- reproduction
- sexual characteristics
- usage and storage of energy
- response to physical stress or trauma
- levels of fluid, salt and sugar in the blood
Hypothalamus
The hypothalamus is located in the center of the brain. 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 also located in the center 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, this master gland regulates the secretions of the thryroid gland, adrenal gland, and testes or ovaries and idrectly secretes the hormones prolactin, vasopressin, and growth hormone.
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.
Adrenal Gland
The adrenal glands are located on top of each kidney. Adrenal glands produce hormones that help the body deal with stress, regulate sexual development and maintain body chemical balance.
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. It produces the insulin necessary for blood sugar control.
Ovary
A female'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, which regulates the menstrual cycle.
Testis
A male's testes are located in the scrotum which hangs suspended outside his body. The testes produce testosterone and sperm.
Revised 9/03, 7/05
