Gastric Motility & Pancreatic Function

Question 1

Body of the stomach has

Answer 1

thin muscle wall - weak contraction

No mixing

Question 2

Antrum of stomach has

Answer 2

thick muscle wall - powerful contraction

mixing, & forcing chyme into duodenum

Question 3

What is chyme?

Answer 3

gastric content

Question 4

What produces gastric peristaltic waves?

Answer 4

Peristaltic rhythm

Question 5

Peristaltic rhythm

Answer 5

(~3/min) generated by pacemaker cells (longitudinal muscle layer)

Question 6

slow wave rhythm =

Answer 6

basic electrical rhythm

Question 7

slow waves -

Answer 7

spontaneous depolarisation/repolarisation

Question 8

slow waves conducted through

Answer 8

gap junctions along longitudinal muscle layer

Question 9

Slow wave depolarisation sub-threshold require further depolarisation to induce

Answer 9

action potentials for contraction

Question 10

More AP waves means stronger

Answer 10

contraction

Question 11

Gastrin & stretching of stomach walls increases

Answer 11

contraction

Question 12

Fat/acid/increase tonicity in duodenum inhibits

Answer 12

motility

Question 13

Bicarbonate secreted in submucosal gland of duodenum to

Answer 13

neutralise acid

Question 14

Control of HCO3 secretion in duodenum:

Answer 14

• Vagus nerve & enteric nervous system

- S cells release secretin

Question 15

what is secretin?

Answer 15

hormone that activates HCO3 release from pancreas & liver

Question 16

3 parts of pancreas

Answer 16

Head
Endocrine part
Exocrine part

Question 17

Head

Answer 17

Head (located within curvature of duodenum), body, tail (extends to spleen)

Question 18

Endocrine part

Answer 18

islet of Langerhans, produce somatostatin (control of insulin and glucagon), glucagon and insulin

Question 19

Exocrine part

Answer 19

acinar cells and lobules

Question 20

Lobules connected by

Answer 20

intercalated ducts then intralobular ducts, and interlobular ducts before secreting into pancreatic duct, bile duct & through Sphincter of Oddi into duodenum

Question 21

Sphincter of Oddi secrete

Answer 21

secrete enzymes and HCO3

Question 22

Exocrine pancreas is responsible for

Answer 22

digestive function of pancreas

Question 23

Functions of exocrine pancreas

Answer 23

Secretion of bicarbonate by duct cells

Secretion of digestive enzymes by acinar cells

Question 24

Zymogens are

Answer 24

inactive form of enzyme

Question 25

Acinar cells of pancreas contains

Answer 25

digestive enzymes stored as inactive zymogen granules

Question 26

Zymogens prevents

Answer 26

autodigestion of pancreas

Question 27

Enterokinase converts

Answer 27

trypsinogen to trypsin

Question 28

Trypsin converts all other zymogens to

Answer 28

active forms

Question 29

Types of pancreatic enzymes:

Answer 29

1. Protease (peptide bonds) 2. Nuclease (hydrolyse DNA/RNA) 3. Elastase (collagen digestion) 4. Phospholipase (phospholipids to fatty acids) 5. Lipase (triglycerides to glycerol & fatty acids) 6. α-amylase (starch to maltose + glucose)

Question 30

Bicarbonate secretion stimulated by

Answer 30

secretin

Question 31

Secretin released in response to

Answer 31

acid in duodenum

Question 32

Zymogen secretion stimulated by

Answer 32

cholecystokinin (CCK)

Question 33

CCK released in response to

Answer 33

fat/amino acids in duodenum