BIOL-242 Lecture Notes - Lecture 41: Thoracic Splanchnic Nerves, Ken Wilber, Pylorus
10 Jun 2020
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Chapter 23 part 3 |function anatomy - the stomach. In upper left quadrant; temporary storage; chemical digestion of bolus to chyme. Pylorus continuous with duodenum through pyloric valve (sphincter controlling stomach emptying) Sympathetic from thoracic splanchnic nerves via celiac plexus. Inner oblique layer allows stomach to churn, mix, move, and physically break down food. Simple columnar epithelium composed of mucous cells. Dotted with gastric pits gastric glands. Mucous neck cells (secrete thin, acidic mucus of unknown function) Glands in fundus and body produce most gastric juice. Ph 1. 5 3. 5 denatures protein, activates pepsin, breaks down plant cell walls, kills many bacteria. Glycoprotein required for absorption of vitamin b12 in small intestine. Without vitamin b12, we get pernicious anemia. Activated to pepsin by hcl and by pepsin itself (a positive feedback mechanism) Damaged epithelial cells quickly replaced by division of stem cells. Inflammation caused by anything that breaches mucosal barrier.
