PHGY 210 Lecture Notes - Enteric Nervous System, Atropine, Neuromuscular Junction

• School: McGill University
• Department: Physiology
• Course: PHGY 210
• Professor: Ann Wechsler

Document Summary

There are sertain regions in which the musculature is striated (eg the pharynx, upper. 1/3 of the esophagus, external anal sphincter, mouth). From below the upper 1/3 of the esophagus to the internal anal sphincter is smooth muscle enteric innervation. Establishment of gradients of pressure results from the coordinated contraction of the muscular elements of the wall of the git (mostly smooth muscle: segmentation: rings of contraction which divide the gut into sausage like sections. Very effectice mixing movement mixing contents back and forth: peristalsis: analogy: taking a tube of toothpaste, squeezing it down so that toothpaste comes out of the tube you are acting like a peristaltic wave. Variations in resistance: normally very little or no resistance, used to be thought that sphincters regulate the flow of contents through tubes. One way valves control movement from one organ to another, close to prevent reflux back into the organ it came from.