Physiology 3120 Lecture Notes - Lecture 16: Autonomic Nervous System, Adrenal Medulla, Somatic Nervous System
1 Feb 2016
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Document Summary
The portion of the nervous system that controls the visceral functions of the body. It has three divisions: sympathetic, parasympathetic and enteric (gut) Essential for control of individual organ function and for homeostasis. Operates in the background (housekeeping) -> e. g. : if a subject stands up from a seated position, the potential situation is blood flowing to legs, 40% decrease in cardiac output, decrease in blood to brain, resulting in fainting. This is prevented by the feedforward arteriole constriction (provided by combination of autonomic nervous system and somatic nervous system) Glands (saliva, sweat, adrenal medulla, digestive, prostate etc) Largely involuntary (rather than voluntary), except for reflexes. Some organs intrinsically active (gut, heart) - ans regulates (increase or decrease activity of heart, increase or decrease peristalsis in the gut) Dual innervations (sympathetic/parasympathetic, one excitatory the other inhibitory) Denervation of organ (e. g. gut, heart) - no atrophy (no ap like in skeletal muscle)
