Gastric Motility and Pancreatic Function

Question 1

what produces a more powerful reaction, the body or the antrum of the stomach?

Answer 1

the antrum due to thick muscle layer

Question 2

how does contraction of the pyloric sphincter cause more mixing of the antral contents?

Answer 2

it stops the chime from entering the duodenum forcing it back up towards the body causing mixing

Question 3

what produces the peristaltic rhythm?

Answer 3

pacemakers in the longitudinal layer of muscle

Question 4

describe the depolarisation produced by slow waves

Answer 4

they are subthreshold and require further depolarisation to produce an action potential

Question 5

what causes an increase in contraction of the stomach?

Answer 5

> distension of the stomach wall

> gastrin

Question 6

what in the duodenum will cause inhibition of motility?

Answer 6

> amino acids
hypertonicity
fat
acid

Question 7

where are brunner’s gland cells located?

Answer 7

in the submucosa of the duodenum

Question 8

what do brunner’s glands release?

Answer 8

bicarbonate HCO3

Question 9

how does the duodenum respond when there is acid?

Answer 9

> long and short reflexes cause the release of bicarbonate
secretin is released from s cells which acts on the liver and the pancreas causing bicarbonate secretion, neutralising the acid

Question 10

what inhibits secretin release?

Answer 10

acid neutralisation (negative feedback)

Question 11

what do islets of Langerhans produce?

Answer 11

> insulin
glucagon
somatostatin

Question 12

describe the journey from the lobules connected by intercalated ducts to the duodenum

Answer 12

> intralobular ducts
> interlobularduct
> main pancreatic duct
> common bile duct
-through the sphincter of oddi-
> duodenum

Question 13

apart from the main pancreatic duct how else may secretions enter the duodenum form the pancreas?

Answer 13

through the accessory pancreatic duct

Question 14

what is the exocrine part of the pancreas responsible for?

Answer 14

the digestive function of the pancreas

Question 15

what do the acini in the pancreas secrete?

Answer 15

digestive enzymes

Question 16

what do the ducts in the exocrine part of the pancreas secrete?

Answer 16

bicarbonate

Question 17

what do acinar cells contain to prevent auto-digestion of the pancreas?

Answer 17

digestive enzymes stored as inactive zymoger granules

Question 18

where are enterokinases found?

Answer 18

bound to the brush border of duodenal enterocytes

Question 19

what is the function of enterokinase?

Answer 19

it converts trypsinogen to trypsin

Question 20

what is the function of trypsin?

Answer 20

it converts zymogens to their active forms

Question 21

name pancreatic enzymes

Answer 21

> nucleases
> proteases
> elastases
> alpha-amylase
> phospholipids
> lipases

Question 22

what is the function of alpha-amylase?

Answer 22

it converts starch into maltose and glucose

Question 23

what would stimulate the release of cholecystokinin?

Answer 23

fatty acid in the duodenum or organic nutrients in the duodenum (neural)

Question 24

what is the effect of cholecystokinin?

Answer 24

zymogen secretion