ANAT 215 Lecture Notes - Lecture 4: Postganglionic Nerve Fibers, Splanchnic Nerves, Autonomic Nervous System

• School: Queen's University
• Department: Anatomy and Cell Biology
• Course: ANAT 215
• Professor: Leslie W Mac Kenzie

Document Summary

Extends to the effector/target organ: afferent pathway for its impulse back to the cns to be processed then a motor response via efferent pathways to original organ where stimulation originated from. Divisions of ans: sympathetic, parasympathetic and also interic (controls the gi tube) Sym. and para affect same target organ but with opposing functions. Sometimes they work together to augment a response. Synapse and postganglionic neurons pass through the gray ramus to the spinal nerve and then onward to the target site (blood vessels, glands and muscles of skin) Preganglionic neurons pass through sympathetic trunk (without synapsing) to synapse in (collateral) prevertebral (celiac, superior and inferior mesenteric) ganglia to form splanchnic nerves which then sends postganglionic neurons to abdominal and pelvic viscera. Preganglionic neurons can travel up or down the sympathetic trunk to another paravertebral ganglia synapse in. Autonomic neurons will follow blood vessels because they lead to their targets. Cn x supplies thorax to the descending colon.