PSL300H1 Study Guide - Midterm Guide: Sympathetic Nervous System, Preganglionic Nerve Fibers, Postganglionic Nerve Fibers
Document Summary
June-04-13 11:40 am sympathetic parasympathetic preganglionic postganglionic sympathetic efferents intromedio-lateral horn vasoconstriction baroreflex. Ans: flight-or-fight response, housekeeping maintenance of the body. thought of as involuntary. part of cns controlling organs , endocrine functions, blood flow and smooth muscles of the eye, etc. Ans supplies almost all organs, in sympathetic and parasympathetic. both activate the same regions. preganglionic axons are myelinated (fast) , postganglionic are unmyelinated (slower, activated by ach). Parasympathetic originates in s. c only, from thoracolumbar regions. preganglion: very small length of axons. Ach then na, can release into circulatory system then target. Ennervate same organs preganglionic axons long originate from brain stem or cranial sacral post ganglion only release ach! and only onto target. ** preganglionic efferent from the intromedio-lateral horn of the thoracic cord (thoracolumbar) **synapse in chain of ganglia parallel to cord, but these neurons aren"t motorneurons!
