LESSON 6
REVIEW OF THE ENDOCRINE SYSTEM
Section I. INTRODUCTION
6-1.
OVERVIEW
a. Many of the drugs you will dispense will directly affect one or more of the
endocrine glands or will perform some function intended to be performed by one of the
endocrine glands. As you review the endocrine system, be aware of the importance of
this system to your daily life.
b. The endocrine system is an interconnected system of glands that produces
substances known as hormones. These glands are not connected directly, but are
nonetheless connected by the circulatory system. The hormones these glands produce
have wide-ranging effects on the body. The production of the proper hormone in the
proper amount at the proper time is absolutely essential for the maintenance of good
health. An imbalance of one of these hormones causes widely varying effects upon the
body.
6-2.
BASIC DEFINITIONS
a. Gland. A gland is a secreting organ. The process of secretion includes the
production of a chemical substance and the release of that substance into the blood or
a body cavity.
b. Hormone. A hormone is a specific chemical substance that is produced in
one organ (that is, endocrine gland) and transported by the blood to distant parts of the
body. The hormones stimulate these various parts of the body to perform a function.
c. Exocrine Glands. The exocrine glands are duct glands. That is, exocrine
glands secrete a chemical substance through a system of ducts into a body cavity or
onto the body surface. Examples of exocrine glands are the liver, salivary glands, and
sweat glands.
d. Endocrine Glands. Endocrine glands are ductless glands. That is,
endocrine glands secrete hormones directly into the bloodstream instead of through a
duct or duct system. Examples of endocrine glands include the pituitary body and the
thyroid gland.
MD0807
6-3