Gastric motility and pancreatic function

Question 1

what part of the stomach has a thin wall and what part has a thick wall? and what does this mean?

Answer 1

the body has a thin muscle wall = weak contraction

the antrum has a thick muscle wall = strong contraction

Question 2

what is at the junction between the stomach and the duodenum?

Answer 2

pyloric sphincter

Question 3

what are the waves called in the stomach during digestion?

Answer 3

gastric peristaltic waves

Question 4

what is the gastric peristaltic wave generated by?

Answer 4

pacemaker cells in the longitudinal muscle layer in the upper part of the gut

Question 5

what is the rate of the gastric peristaltic waves?

Answer 5

3/m

Question 6

what is the basic electrical rhythm?

Answer 6

small waves generated by spontaneous de and re polarisation

Question 7

slow waves are conducted through what type of junction between the cells in the longitudinal layer?

Answer 7

gap junctions

Question 8

does gastrin increase or decrease contraction?

Answer 8

increases

Question 9

what will inhibit the stomach motility?

Answer 9

acid, fat, amino acids, hypertonicity in the duodenum

this indicates that the food has passed into the duodenum

Question 10

there is a constant underlying electrical event and contraction only occurs when it reaches threshold. what will trigger an action potential in these cells for contraction?

Answer 10

gastrin

ACh

Question 11

in the stomach where is bicarbonate HC03 produced from?

Answer 11

Brunners gland duct cells

Question 12

what controls bicarbonate secretion from the duodenum?

Answer 12

acid in the duodenum triggers long and short reflexes which trigger HC03 secretion
it also triggers the release of secretin from S cells which causes HC03 secretion from the duodenum, pancreas and liver

Question 13

give an example of the control of bicarbonate a negative feedback mechanism?

Answer 13

when seretin triggers the release of HC03 this causes acid neutralisation
acid neutralisation then inhibits secretin production

Question 14

where in the pancreas is insulin and glucagonproduced from?

Answer 14

the pancreatic islets
alpha cells = glucagon
beta cells = insulin

Question 15

what does the main pancreatic duct feed into?

Answer 15

common bile duct

Question 16

where are the products from the pancreatic islets released to?

Answer 16

into the bloodstream

exocrine portion

Question 17

what part of the pancreas produces the pancreatic enzymes for digestion?

Answer 17

Acini

Question 18

acini in the pancreas feed into what?

Answer 18

intercalated ducts –> intralobular ducts –> interlobular ducts –> pancreatic duct –> common bile duct

Question 19

what is the function of the duct cells in the pancreas?

Answer 19

produce bicarbonate

Question 20

what is the function of the acinar cells?

Answer 20

produce pancreatic lipases (digestive enzymes)

Question 21

what is the name for the inactive enzymes the pancreas makes?

Answer 21

zymogens

Question 22

what is the function of enterokinase?

Answer 22

converts trypsinogen to trypsin

trypsin then activates another inactive enzymes

Question 23

where is enterokinase found?

Answer 23

brush border of duodenal enterocytes (surface)

Question 24

what is the function of pancreatic lipases?

Answer 24

converts triacylglycerols to diglycerols + 2 fatty acids

Question 25

what is the function of alpha amylase?

Answer 25

breaks down di and try glycerides to monoglycerides

breaks glycosidic bonds

Question 26

zymogen secretion is stimulated by?

Answer 26

CCK

Question 27

seretin is released in response to ……. which causes?

Answer 27

acid in the duodenum

secretin triggers secretion of bicarbonate