Autonomic nervous system receptor characteristics

The autonomic nervous system (ANS) is the major involuntary, unconscious, automatic portion of the nervous system and contrasts in several ways with the somatic (voluntary) nervous system. The anatomy, neurotransmitter chemistry, receptor characteristics, and functional integration of the ANS are discussed below. 

Muscarinic receptors are found in both the brain and the peripheral nervous system. In the latter, they are within the autonomic (involuntary) nervous system where they control functions within the respiratory, cardiac, alimentary and urogenital systems. This is important in understanding the toxidromes (characteristic collections of signs and symptoms) which arise after toxic exposure. In the central nervous system (CNS), the muscarinic receptors are present in high proportions within several difference subtypes which are listed in Box 6.3. 

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