Chapter Eighteen

The Endocrine System

It is helpful to know the location and purpose of the endocrine system.

The endocrine system is a complex system of glands that produce and secrete hormones directly into the circulatory system to influence, regulate and control metabolism and many of the body’s processes.

1. Pineal: cone-shaped gland at the base of the brain that secretes the hormone melatonin, which may help to synchronize biorhythms and mark the passage of time.

2. Pituitary: the body’s “master gland,” which stimulates the adrenals, thyroid, pigmentation-producing skin cells and gonads. Also secretes growth hormone, the antidiuretic hormone prolactin, and oxytocin, a hormone that causes contractions of the uterus during labor.

3. Thyroid: produces the hormones thyroxine, triiodothyronine, and calcitonin, which stimulate metabolism, body heat production and bone growth.

4. Parathyroid: endocrine glands whose hormones regulate the use and function of calcium and phosphorus in the body.

5. Thymus: gland located behind the breastbone that is important in the development of cell-mediated immune responses.

6. Adrenals: release hydrocortisone, which effects metabolism. Also produce androgen honnones and aldosterone hormone, which maintains blood pressure and the body’s salt and potassium balance.

7. Pancreas: abdominal organ, secretes insulin and glucagon, which control the utilization of sugar, the body’s chief source of energy.

8. Ovaries (not shown): female glands that produce the hormones estrogen and progesterone, which influence female physiology

9. Testes (not shown): male glands secrete testosterone, which stimulates sperm production and development of male characteristics.*

Chapter Eighteen

Date: 2015-02-16; view: 822