Autonomic Nervous System

The autonomic nervous system is responsible for maintaining physiologic homeostasis. Thus it regulates the actions of the cardiovascular and respiratory systems as well many other bodily functions. Specific physiologic responses are linked to its major divisions, the sympathetic nervous system and the parasympathetic nervous system.

The neurotransmitters associated with the sympathetic nervous system are the catecholamines, epinephrine and norepinephrine. The responses that they elicit are termed adrenergic responses and are categorized as either alpha or beta adrenergic responses.

Acetylcholine is the neurotransmitter for the parasympathetic nervous system. The responses elicited are considered to be cholinergic responses. Although these responses seem to be counter regulatory in terms of the sympathetic responses, the two systems interact to maintain physiologic homeostasis.

One of the theories of emotional disturbances states that alterations in the levels of neurotransmitters may be related to the development of these illnesses.

Medications that interact with the autonomic nervous system are used in a variety of disease states.

Critical Thinking:

What cardiorespiratory changes would occur with an exacerbation of either the Parasympathetic Nervous System or the Sympathetic Nervous System?

Email answers to: frizzell@lasalle.edu

Ó JPFrizzell 1999