Endocrine Glands

A. Glands without ducts

1. Secrete HORMONES (“ to set in motion ”) into the intercellular spaces and they pass directly into the blood and is then distributed to all parts of the body via they circulatory system.

2. Hormones – chemical secretions of the endocrine glands.

   1. chemical types -

1). proteins and polypeptides (endodermal origin)

2). amines (endodermal origin)

3). steroid (mesodermal origin)

3. Hormones – act to maintain homeostasis by altering cellular activity.

4. Hormones – can effect
   

a. organ or groups of organs directly (“target organ(s)”)

b. other endocrine glands called “target glands”

[these hormones are called trophic hormones]

B. Nervous System vs. Endocrine System

Controls muscles & glands activities of cells:

1. metabolism

2. reproduction

3. stress responses

4. fluid-electrolyte balance

5. acid-base balance
   

6. energy balance

Category: Physiology Notes