Physiology 1021 Lecture 4: 4 - The Autonomic Nervous System

• School: Western University
• Department: Physiology
• Course: Physiology 1021
• Professor: John Ciriello

Document Summary

Nerve fibers of the autonomic nervous system innervate cardiac muscle, smooth muscle, and glands. Ans is found throughout the neuro axis (central and peripheral) found everywhere! Divided into the sympathetic and parasympathetic nervous systems. The ans is a two neuron system (contains a preganglionic neuron and a postganglionic neuron) Long, non-myelinated postganglionic neuron (slower signal transmission: many target tissues (not specific, neurotransmitters. For blood vessels and in the skeletal muscle - acetylcholine (ach) Short postganglionic neuron: more specificity in target. Differences in anatomical and neurochemical organization of the sympathetic nervous system. Preganglionic connects to postganglionic neuron for all effectors, except the adrenal gland. Exception: in the adrenal medulla, the preganglionic neuron sy(cid:374)apses with a chro(cid:373)affi(cid:374) cell adre(cid:374)ali(cid:374)e/ epi(cid:374)ephrine. Every preganglionic neuron (sns + psns) releases ach. Norepinephrine acts at b (heart and coronary blood vessels) or a receptors - exception: the sns postganglionic neuron releases ach at blood vessels in skeletal muscle. There is no parasympathetic innervation of: blood vessels.