Physiology final- digestive system

Question 1

4 processes of the digestive system

Answer 1

motility, secretion, digestion and absorption

Question 2

Muscularis Externa

Answer 2

major smooth muscle that lines digestive tract. circular inner layer and longitudinal outer layer.

Question 3

digestive muscles

Answer 3

innervated by the vagus nerve and the parasympathetic nervous system.

Question 4

Gastric Emptying

Answer 4

factors in the stomach: amount of chyme in stomach influences strength of contraction. Factors in Duodenum: fat, acid, hypertonicity, and distension (too much stuff in stomach)

Question 5

Chief Cells

Answer 5

produce pepsinogen and when activated begin protein digestion

Question 6

Parietal Cells

Answer 6

secrete HCl

Question 7

Gastric mucosal Barrier

Answer 7

enables stomach to contain acid without injuring itself

Question 8

Pancreatic secretion is regulated by

Answer 8

CCK (regulates gall bladder contraction) and secretin

Question 9

Secretin

Answer 9

stimulates secretion of bicarbonate in response to low stomach pH/acidic levels.

Question 10

CCK

Answer 10

Digests fat and protein. signals the gall bladder to contract. negative feedback loop for satiety, tells you to stop eating.

Question 11

liver

Answer 11

largest and most metabolic organ in the body. makes and secretes bile salts

Question 12

gall bladder

Answer 12

sits under the liver. release of bile comes from cck. common bile duct takes bile from the gall bladder to the lumen of the small intestine.

Question 13

hepatic portal vein

Answer 13

takes drained blood from the digestive tract to the liver for processing and storage of absorbed nutrients. blood also then leaves the liver through the hepatic portal vein back to the heart. fat doesn’t go to the liver for absorption

Question 14

Bile

Answer 14

made by hepatocytes, stored and concentrated in the gall bladder. made up of bile salts, cholesterol, lecithin and bilirubin

Question 15

Bile salts

Answer 15

derivatives of cholesterol to break up fats into smaller molecules. function as detergents. 95% of bile salts are reabsorbed by the terminal ileum.

Question 16

Liver functions not related to digestion

Answer 16

makes bile, detoxifying or degrading body wastes, synthesizes plasma proteins, stores glycogen, removes bacteria and worn out rbc’s

Question 17

brush-border enzymes

Answer 17

fixed on microvilli in the small intestine. activate enzymes that break down proteins and carbs. not secreted into the lumen.

Question 18

small intestine

Answer 18

almost all absorption occurs here. brush-border enzymes are here

Question 19

tripsinogen

Answer 19

made in the pancreas and is activated by brush-border enzymes to make active tripsin.

Question 20

digestion and absorption of carbs

Answer 20

carbs break down lactose, maltose and sucrose into monosaccharides. secondary active transport by sodium is used to move glucose from lumen into the capillary venous space.

Question 21

digestion and absorption of fats

Answer 21

bile salts coat fat droplets. pancreatic lipase breaks fats down into monoglycerides and fatty acids stored in micelles. monoglycerides and fatty acids then move out of micelles. monoglycerides and fatty acids move in through diffusion and cholesterol is transported into the cell. everything is added back together in the cell and make chylomicrons and moved to the lymphatic system to make lacteal.

Question 22

Gastrin (G cells)

Answer 22

stomach cells, stimulate parietal cells

Question 23

zymogens

Answer 23

inactive, secreted by the pancreas into the lumen of the small intestine to be activated. includes tripsinogen.