PHGY 210 Study Guide - Final Guide: Myenteric Plexus, Submucous Plexus, Enteric Nervous System
17 Oct 2016
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Document Summary
The basis of the digestive system is to intake food, process it into manageable forms (ffas, ), absorb useful nutrients and excrete waste: open found in earthworms. Food enters one end (anterior) and exits another (posterior). In higher organisms, the gi-tract both grows (4. 5m long in an adult human male, with several infoldings to maximize absorption) and differentiates into several physiologically distinct structures. Anatomy of the gi-tract from outermost to innermost. Keep in mind that the muscle in the top third of the digestive system and the anal sphincter is striated (under voluntary control). Outermost layer serosa tough connective tissue. Attached to the abdominal wall to support the gi-tract. Muscularis externa layers of smooth muscle that cause contractions necessary for moving food. Longitudinal muscle outermost layer of muscle that causes longitudinal contractions (shortening of the gi-tract). Myenteric plexus neuronal network that lies between muscle layers. Talks to the gi epithelium and submucosal plexus via enteric fibers.
