ANP 1106 Chapter Notes - Chapter 14: Pelvic Splanchnic Nerves, Dorsal Root Ganglion, Inferior Hypogastric Plexus

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1106
• Professor: Jackie Carnegie

Document Summary

Autonomic nervous system (ans): motor neurons that innervate smooth and cardiac muscle and glands. Make adjustments to ensure optimal support for body activities (regulate homeostasis: speed up/slow down heart rate, shunt blood where needed, adjust bp and body temp, etc. Effectors ans innervates mostly visceral organs (stomach, intestine, liver, spleen, pancreas, kidney, etc. Efferent pathways and ganglia axons of ans uses a two-neuron chain to reach its effectors: Preganglionic neuron cell body (first neuron) is found in the brain or spinal cord, and the preganglionic axon synapses with the second motor neuron; its axon is lightly myelinated and it extends to a peripheral ganglion. Neurotransmitter effects ans postganglionic fiber release two neurotransmitters: norepinephrine (secreted by sympathetic fibers) and ach (secreted by parasympathetic fibers) Postganglionic fibers release norepinephrine or ach and the effect is either stimulatory or inhibitory, it depends on the type of receptors on the target organ. Preganglionic fibers release ach only (to excite the postganglionic fiber)