Flashcards in Physiology Deck (187)
What are the layers of the GI wall?
Circular & longitudinal smooth muscle
What is part of the mucosa?
Layer of epithelial cells specialized for absorption and secretion
What is the submucosa consist of?
Consists of collagen, elastin, glands, and blood vessels
What is the circular and longitudinal smooth muscle for?
Motility for GI tract
Functions of the Mouth
Mostly mechanical digestion
Food is broken down into small particles
Enzymes of the Mouth
Lingual amylase: carbs
Lingual lipase: lipids
What does lipase require to function appropriately?
How many muscles and CN are used for swallowing?
What CN are used for swallowing?
Esophageal Stage of Swallowing
Begins with crico-pharyngeal relaxation
What salivary gland matches up with Stenson's duct?
What salivary glands match up with Wharton's ducts?
What salivary glands match up with the sublingual ducts?
How much saliva does the salivary glands produce a day?
Functions of Saliva
Initial digestion of starches & lipids by salivary enzymes
Dilution & buffering of ingested foods
Lubrication of ingested food to aid its movement
Secretions Produced By:
Gastric mucosal cells
Pancreatic exocrine cells
Functions of the Stomach
Liquefaction of food
Release slowly into sm. intestine
Pepsin & peptidase to break down proteins
Good environment for enzymes to work in
Functions of the Small Intestine
Absorption of nutrients
Function of the Large Intestine
Absorption of water
What does gastric juice convert food to?
Semiliquid called chyme
4 Parts of the Stomach
What are the 3 phases of digestion?
Parts of the brain that are part of the cephalic phase
Important Hormones of the Gastric Phase
hormones in the GI tract as a group
Define Intestinal Phase
Enterogastrone hormones secreted in the duodenum & the lower GI tract
What does stimulation of the vagal nerve fibers cause release of?
Pancreatic juice and weak contractions of the gallbladder
What is released during the gastric phase of digestion?
Cholecystokinin into the blood stream
What happens when cholecystokinin reaches the pancreas?
Induces secretion of enzyme-rich pancreatic juice