Flashcards in GI Physiology Deck (60):
Most potent stimuli for gastrin secretion
Phenylalanine, tryptophan, methionine
Neurocrine from vagus nerve to G cells
GI Hormone classified as incretin
GIP, GLP-1, glucagon
GI hormone responsible for the interdigestive/migrating myoelectric complex
Inhibits appetite; found at the ventromedial hypothalamus
Stimulates appetite; found at the lateral hypothalamic area
Appetite/ hunger center
Sends signals to satiety & hunger centers
Releases POMC to decrease appetite
Releases Neuropeptide Y to increase appetite
Stimulates anorexigenic neurons, inhibits orexigenic neurons
Leptin (fat cells), insulin, GLP-1
Inhibit anorexigenic neurons
Ghrelin (gastric cells)
What is the most common stimulus of peristalsis?
What is the myenteric reflex?
Muscles upstream contract, muscles downstream exhibit receptive relaxation
What is the law of the gut?
Myenteric reflex + anal direction of peristalsis
How long does it take to transfer material from pylorus to ileocecal valve?
How long does it take to transfer material from ileocecal valve to colon?
Receptive relaxation of the stomach, vasovagal reflex mediated by
Capacity of the stomach
1.5 L or 400g of food
Gastric emptying duration
Inhibitor of gastric emptying
Urge to defecate, once rectum is
Saliva, serous secretion
Saliva, mixed secretion
Submandibular, sublingual glands
Saliva, effect of parasympa NS
Increase salivation, serous
Effect of sympa NS
Increase salivation, mucoid
Initial saliva is high in
Final saliva is high in
Hormone involved in absorbing Na at the ductal cells
At high flow rates, saliva has
Low K; High Na, Cl, HCO3
At low flow rates, saliva has
High K; Low Na, Cl, HCO3
Contains mucus neck cells, parietal cells & chief cells
Oxyntic glands (body)
Contains G cells, mucus cells
Pyloric glands (antrum)
Secretes mucus & HCO3
Mucus cells, mucus neck cells
Secretes HCl & IF
Parietal cells/ Oxyntic cells
Enterochromaffin-like (ECL) cells
How do you absorb glucose & galactose from lumen to intestinal cells
How do you absorb fructose from lumen to intestinal cell?
How do you absorb glucose, galactose & fructose from intestinal cell to blood?
What is the optimum pH for pepsin activity?
pH 1.0 - 3.0
Which is essential for protein digestion, pepsin or trypsin?
Bile salts inactivates pancreatic lipase. What pancreatic coenzyme is secreted to prevent this from happening?
Procolipase to colipase
What is the only product of TAG metabolism that is NOT hydrophobic?
What type of fatty acids go directly to the portal vein instead of the lacteals?
Short chain & medium chain FA
Main site for water reabsorption
Potassium is absorbed at
Potassium is secreted at
Primary ion secreted in the intestinal lumen
Needed to absorb Vit B12
Needed to absorb calcium
1,25 (OH)2 cholecalciferol/ Calcitriol
Needed to absorb iron
Part of the metabolism of these vitamins involves colonic flora
Vit K, B1, B2, B12
Liver zone first to encounter toxins
Zone 1 (peripheral)
Liver zone susceptible to hypoxia
Zone 3 (centrilobular)
Space of Disse; Vitamin A storage