GI

Question 1

Cephalic phase

Answer 1

• the though, sight, smell and taste of food will stimulate the vagal pathway.
• salivary secretion and excitation of the stomach
• pepsinogen and gastrin will be secreted into stomach.
• stimulating the secretion of HCL and enzymes from pancreatic acinar cells.

Question 2

Gastric phase

Answer 2

-Vagovagal response
- gastrin and histamine secretion will increase acid production

Question 3

Intestinal phase

Answer 3

• further breakdown and absorption of nutrients
• amino acids and fatty acids will stimulate the release of CCK and secretin into the small intestine.
• cck will cause contraction of the gallbladder (increase bile secretion) and stimulate acinar cells in the pancreas to secret digestive enzymes.

Question 4

Purpose of secretin and cck?

Answer 4

CCK= contraction of the gallbladder
Secretin = aids in amplification of bile production of the liver and stimulates the pancreas to release enzymes and bicarbonate to neutralise chyme.

Question 5

What can CCK and secretin work together to do?

Answer 5

They can act together to inhibit peristaltic movements to allow for proper absorption.

Question 6

What is the purpose of amylase and saliva mixing with food in the mouth?

Answer 6

They will improve the environment for stomach enzymes and make the food easier to swallow.
It also allows amylase to start digesting carbs.

Question 7

4 phases of swallowing

Answer 7

Voluntary
Pharyngeal
No name
Oesophageal

Question 8

Migrating motor complex

Answer 8

Prevent bacterial overgrowth and keeps stomach and intestine clean.
Stimulated by motilin (a hormones released during fasted state)

Question 9

Segmentation

Answer 9

• Mixing chyme with secretions and mucosa.
• contraction of the circular muscle layer.

Question 10

Peristalsis

Answer 10

Propels chyme along the small intestine via contraction of the longitudinal smooth muscle

Question 11

main pancreatic blood supply?

Answer 11

splenic artery (from coeliac trunk)
pancreatic-duodenal arteries (from super mesenteric artery)

Question 12

endocrine pancreas

Answer 12

islets of langerhans - insulin and glucagon

Question 13

exocrine pancreas

Answer 13

bicarbonate and enzyme
the bicarbonate is what gives the pancreas its high alkalinity .

Question 14

what stimulates duct cell secretion from of bicarbonate?

Answer 14

• secretin (increases cAMP levels)
• Ach (increase Ca levels)

Question 15

how does the Cl-/HCO3- exchanger work?

Answer 15

carbonic anhydrase will catalyse the release of CL- through the CFTR chloride channel, allowing the chloride to re-enter the cell through the Cl/HCO3 channel. this moves bicarbonate out and Cl back in.

Question 16

when bicarbonate moves out of the duct cells, what will move with it?

Answer 16

sodium and water will follow the bicarbonate paracellular

Question 17

what inhibits bicarbonate secretion?

Answer 17

substance P

Question 18

what makes up the portal triad?

Answer 18

hepatic artery
portal vein
bile duct

Question 19

what regulates flow in and out of the gallbladder

Answer 19

valve of Hiester

Question 20

cholestasis

Answer 20

• suppression of bile secretion (nothing moving)
• regurgitation of bile components leading to juandice and itching
• damage to hepatocytes
• caused by mechanical obstruction

Question 21

gallstones

Answer 21

disturbance of bile secretion and and cholesterol elimination leading to a build of of cholesterol

Question 22

liver functions

Answer 22

• synthesis and secretion of bile
• metabolism and storage of carbs, lipids, proteins and vitamins
• detoxification
• synthesis of blood clotting
• immune system function

Question 23

kupffer cells

Answer 23

removal of intestinal bacteria from portal blood to keep systemic circulation clear.