Gastric Motility and Pancreatic Function

Question 1

What is the effect of peristaltic waves on the body of the stomach?

Answer 1

Weak contraction (no mixing)

Question 2

What is the effect of peristaltic waves on the antrum?

Answer 2

Powerful contraction
Mixing
Contraction of the pyloric sphincter

Question 3

What is the purpose of contracting the pyloric sphincter?

Answer 3

Small amount of chyme entering duodenum

Most of antral contents moved backwards

Question 4

What is the rate of peristaltic rhythm?

Answer 4

3/min

Question 5

Pacemaker cells of peristaltic rhythm are situated where?

Answer 5

Longitudinal muscle layer of muscularis externa

Question 6

What is the Basic electrical rhythm of the gastric system?

Answer 6

Spontaneous slow wave depolarisation through gap junctions

Question 7

Number of Action potentials determines what?

Answer 7

Contraction STRENGTH

Question 8

What is the effect of gastrin on the peristaltic waves?

Answer 8

Stronger contractions

Question 9

Distension of the stomach wall causes what?

Answer 9

Long reflexes (vagus nerve)
Short reflexes (ENS)

Question 10

Distension reflexes have what effect?

Answer 10

Increased contraction

Question 11

What is the effect of food particles in the duodenum?

Answer 11

Mobility inhibition

Question 12

How is acid neutralised in the duodenum?

Answer 12

Secretion of Bicarbonate (HCO3)

Question 13

Where is Bicarbonate secreted from in the duodenum?

Answer 13

Brunner’s Gland duct cells

Question 14

Why does the oesophagus produce bicarbonate?

Answer 14

Increase the speed of food passage

Question 15

Acid and Bicarbonate forms what?

Answer 15

H2CO3

–> H20 + CO2

Question 16

Acid in the duodenum triggers what?

Answer 16

Long and short reflexes for HCO3 secretion

Release of secretin for HCO3 secretion

Question 17

Secretin release triggers what?

Answer 17

HCO3 secretion from pancreas and liver

Question 18

How is secretin release inhibited?

Answer 18

Acid neutralisation

Question 19

Islet cells of the pancreas produce what?

Answer 19

(Endocrine)
Insulin
Glucagon
Somatostatin

Question 20

The exocrine pancreas produces what?

Answer 20

Bicarbonate

Digestive Enzymes

Question 21

What is the sequence followed leaving the acini cells of the pancreas?

Answer 21

Acini cell
Intercalated duct
Intralobular duct
Interlobular duct

Question 22

Bicarbonate is produced by what in the pancreas?

Answer 22

Duct cells

Question 23

Digestive enzymes are produced by what in the pancreas?

Answer 23

Acinar cells

Question 24

The pancreatic duct meets the duodenum where?

Answer 24

Sphincter of oddi

+ accessory duct

Question 25

What are Zymogens?

Answer 25

Inactive forms of digestive enzymes

Question 26

Why does the pancreas store digestive enzymes as zymogens?

Answer 26

Prevention of autodigestion

Question 27

How are Zymogens activated?

Answer 27

Contact with enterokinase on brush border membrane

Question 28

Enterokinase converts what?

Answer 28

Trypsinogen to trypsin

Question 29

What is the role of trypsin?

Answer 29

Converts all other zymogens into their active form

Question 30

Enterokinase is presented where?

Answer 30

Brush border of duodenal enterocytes

Question 31

What are the categories of pancreatic enzymes?

Answer 31

Proteases, nucleases, Elastases, Phospholipases, Lipases, a-amylase

Question 32

What is the role of nucleases?

Answer 32

Hydrolise DNA/RNA

Question 33

What is the role of elastases?

Answer 33

Digest collagen

Question 34

What is the role of phospholipase?

Answer 34

Convert phospholipids to FAs

Question 35

What is the role of lipases?

Answer 35

Convert TAGs to FAs+Glycerol

Question 36

What stimulates the secretion of bicarbonate in the pancreas?

Answer 36

Secretin in response to acid in duodenum

Question 37

What stimulates the secretion of zymogen from the pancreas?

Answer 37

Cholecystokinin (CCK) release in response to Fat/AAs in duodenum

Question 38

Organic nutrients in the duodenum trigger what?

Answer 38

Neural/reflex triggering pancreatic function