Autonomic nervous system

1. 3 primary functions of the ANS: regulation of the heart, secretory glands (salivary,

gastric, sweat, and bronchial glands), and smooth muscles (muscles of bronchi, blood

vessels, urogenital system, and GI tract).

2. A branch of the CNS

3. Regulated by the: hypothalamus, brain stem, and spinal cord

4. Requires no conscious or action (just happens)

5. Maintains homeostasis by regulating processessuch as body temperature, responds to

stress and emergencies

6. Nerve impulses are transmitted in the same way as the CNS

ANS is divided into Sympathetic Nervous System (SNS) and Parasympathetic Nervous system (PNS)

• The two systems keep each other in balance. The SNS excites and the PNS inhibits.

1. The branch of the ANS that controls organ function most of the time is said to provide

the predominant tone to that organ. In most organs, the PNS provide the predominant

tone. The vascular system, which is regulated almost exclusively by the SNS, is the

principle exception.