Test Bank For Essentials of Anatomy and Physiology (NOTES) by Frederic H. Martini. LATEST UPDATED VERSION

Test Bank For Essentials of Anatomy and Physiology (NOTES) by Frederic H. Martini. LATEST UPDATED VERSION Stomach, gastric wall (secretions) & regulation of gastric activity 4 Functions of The Stomach. Temporary Storage  Mechanical breakdown Digestion(acids and enzymes)  Production of Intrinsic factor Secretory cells and their secretions. Gastric glandsare dominated by 2 types of secretory cells that secrete about 1500ML of Gastric juiceeach day. Parietal cells- secrete intrinsic factor and hydrochloric acid(HCL) Chief Cells - secrete a protein called Pepsinogen into the stomach lumen. Production of acid & enzymes by stomach mucosa is regulated by: CNS Reflexes within the walls of the stomach Hormones of the digestive tract Regulation of Gastric Activity(3 phases). Cephalic phase - Begins when you sense or think of food. Gastric phase - Begins when food arrives in the stomach. Intestinal phase - Begins when chyme first enters the duodenum of the small intestine. Digestion in The Stomach. For 1-2 hours after meal Digestion of carbohydrates by salivary amylase & lipids by lingual lipase Until PH falls below 4.5 As PH decreases: Pepsin activity - Protein digestion begins Nutrients cannot be absorbed in the stomach because: Epithelial cells are covered by a blanket of alkaline mucus and are not directly exposed to chyme Epithelial cells lack the specialized transport mechanisms found in cells lining the small intestine Gastric lining is impermeable to water  Digestion has not proceeded to completion by the time chyme leaves the stomach. SU 1_Study sections 1.1-1.3, Martini Chapter 16 Functions & structure of the digestive tract; peristalsis & segmentation 6 Functions of Digestive System. Ingestion Mechanical Processing/Digestion Chemical Digestion Secretion Absorption Excretion