Gastric Motility and Pancreatic Function

Question 1

What part of the stomach has the thickest muscle layer and why?

Answer 1

Antrum because this is where the majority of motility occurs

Question 2

What kind of muscle layer does the body have?

Answer 2

Thin muscle layer for weaker contractions

Question 3

Does the fundus contain muscle?

Answer 3

Yes, but it is relatively little

Question 4

How much gastric content (Chyme) enters the duodenum at a time?

Answer 4

Small amounts and as the sphincter contracts the antral contents are pushed back into the body for more mixing

Question 5

What generates the peristaltic rhythm?

Answer 5

Pacemaker cells found in the longitudinal muscle layer

Question 6

What does the slow wave rhythm create?

Answer 6

The Basic Electrical Rhythm (BER)

Slow waves due to slow de/repolarisation

Question 7

How are the fibres connected?

Answer 7

By gap junctions so electrical activity spreads

Question 8

What does gastrin lead to?

Answer 8

Increased contraction

Question 9

What does stomach distension lead to?

Answer 9

Long/Short reflexes

Increased contraction

Question 10

What inhibits motility?

Answer 10

Fat/Acid/Amino Acid/Hypertonicity in the duodenum

Question 11

What is the other name for submucosal glands that secrete bicarbonate?

Answer 11

Brunner’s Gland duct cells

Question 12

Why is bicarbonate needed to neutralise stomach pH?

Answer 12

Pancreatic enzymes are denatured at stomach pH so this must be resolved

Question 13

What does acid in the duodenum trigger?

Answer 13

Bicarbonate secretion via Long (Vagal) & Short (ENS) reflexes and release of secretin from S cells

Question 14

What does secretin stimulate?

Answer 14

Brunner’s Gland

Question 15

Where does the acid and bicarbonate come from?

Answer 15

Acid comes down into the duodenum from the stomach

Bicarbonate comes up from the submucosa of the duodenum

Question 16

What two functions does the pancreas have?

Answer 16

Exocrine

Endocrine

Question 17

What does endocrine control?

Answer 17

Metabolism

Question 18

Which cells create Insulin and Glucagon to control blood sugar levels?

Answer 18

Islets of Langerhans

Question 19

What hormone controls the Insulin and Glucagon levels?

Answer 19

Somatostatin

Question 20

What are the two functions of the exocrine part of the pancreas?

Answer 20

Aids digestion by secretion of digestive enzymes from acinar cells
Secretion of bicarbonate by duct cells (In response to secretin)

Question 21

What is found in the exocrine part of the pancreas?

Answer 21

Acinar cells

Lobules

Question 22

The pancreatic join the bile duct and joins the duodenum where?

Answer 22

Sphincter of Oddi

Question 23

What opens up if the main pancreatic duct is blocked?

Answer 23

The accessory duct

Question 24

How are the acinar arranged?

Answer 24

Triangularly to make the gland

Question 25

What are digestive enzymes stored as inside the acinar cells?

Answer 25

Inactive zymogen granules

Question 26

What converts Trypsinogen to Trypsin and where is it bound?

Answer 26

Enterokinase

Brush border of duodenal enterocytes

Question 27

What does Trypsin do?

Answer 27

Converts all other zymogens to active forms

Question 28

What stimulates zymogen secretion?

Answer 28

Cholecystokinin (CCK)

CCK is also released in response to fat and acid in the duodenum

Question 29

What type of control is CCK under?

Answer 29

Zymogen - Triggered by the arrival of organic nutrients in the duodenum

Question 30

Where does CCK come from and what is special about it and Secretion?

Answer 30

Duodenal mucosa

They react synergistically together

Question 31

What are the 6 types of pancreatic enzymes?

Answer 31

Proteases
Lipases
α-Amylase 
Phospholipases - Phospholipids to fatty acids
Nucleases
Elastases

Question 32

Where is the H/K pump located for Hydrogen ion secretion?

Answer 32

Cannalicular membrane

Question 33

What hormone inhibits Gastric Acid secretion?

Answer 33

Somatostatin