Lecture 21: STOMACH AND PANCREAS

Question 1

What is the shape of the stomach?

Answer 1

J-shaped organ

Question 2

Where is the stomach located?

Answer 2

At the base of the esophagus

Question 3

What does the esophagus pass through?

Answer 3

The diaphragm at the oesophageal hiatus

Question 4

What does the lower oesophageal sphincter do?

Answer 4

Prevent reflux. Relaxes to let food through and contracts to prevent reflux

Question 5

What are the main parts of the stomach?

Answer 5

Cardia, fundus, body and pylorus (pyloric antrum)

Question 6

What does the lesser omentum do?

Answer 6

Connects the lesser curvature of the stomach to the liver

Question 7

What does the greater omentum do?

Answer 7

Connects the greater curvature of the stomach to the transverse colon

Question 8

What does the greater omentum contain?

Answer 8

Blood vessels, fat and immune cells

Question 9

What is the muscularis of the stomach modified for?

Answer 9

Motility

Question 10

What are the layers of the stomach muscularis?

Answer 10

Oblique (inner), circular (middle) and longitudinal (outer)

Question 11

What is the thickness of the muscularis of the stomach?

Answer 11

Thicker in the pylorus (distal) compared to the cardia (proximal) as there is more mechanical digestion here

Question 12

What are rugae?

Answer 12

Temporary folds that allow for the expansion of the stomach

Question 13

What volume can the stomach expand to?

Answer 13

1.5L

Question 14

What is the rugae important for?

Answer 14

Storage, as well as the sphincters

Question 15

What is the structure of rugae?

Answer 15

They have a folded core of submucosa with overlying mucosa

Question 16

What is the epithelium of gastric gland mucosa?

Answer 16

Simple columnar

Question 17

What does folding of the gastric gland mucosa do?

Answer 17

Increase surface area for secretion (3L/day)

Question 18

What are gastric glands?

Answer 18

Permanent

Question 19

Where re gastric glands found?

Answer 19

In the mucosa only

Question 20

What do we need from the gastric glands?

Answer 20

Acid and enzymes for digestion, mucous for protection and hormones for regulation of secretory and motility events

Question 21

What cells are in the gastric pits?

Answer 21

Goblet cells

Question 22

What do the goblet cells do?

Answer 22

Secrete mucous for protection

Question 23

What cells are in the gastric glands?

Answer 23

Parietal cells, G cells and chief cells

Question 24

What do parietal cells do?

Answer 24

Secrete acid (particularly HCl) and intrinsic factor (important for vitamin B12 absorption)

Question 25

What do G cells do?

Answer 25

Secrete hormones (gastrin)

Question 26

What do chief cells do?

Answer 26

Secrete pepsinogen (an inactive precursor of pepsin which digests proteins)

Question 27

What do chief cells produce?

Answer 27

Enzymes

Question 28

What is abundant in chief cells?

Answer 28

Rough endoplasmic reticulum (as making proteins)

Question 29

What is apical in chief cells?

Answer 29

Zymogen granules (contain enzymes to be exocytosed)

Question 30

What is basal in chief cells?

Answer 30

Nucleus

Question 31

What do parietal cells produce?

Answer 31

Acid

Question 32

What is abundant in parietal cells?

Answer 32

Mitochondria

Question 33

What do parietal cells do?

Answer 33

Pump hydrogen ions

Question 34

Where is the nucleus of parietal cells?

Answer 34

central

Question 35

Why is the parietal cell membrane folded?

Answer 35

To increase surface area for ion pumps for secretion

Question 36

What is the endocrine control of the stomach?

Answer 36

Endocrine cells of mucosa, gastrin and ghrelin secreted into the bloodstream

Question 37

What is the neural control of the stomach?

Answer 37

enteric nervous system (ENS) - local reflexes (primary control), CNS modulates ENS function- long neural reflexes

Question 38

What is needed between the stomach and small intestine?

Answer 38

Controlled releasee of digested material (chyme)

Question 39

How is controlled releasee into the SI achieved?

Answer 39

Pyloric sphincter

Question 40

What does acidic chyme do?

Answer 40

Enter the small intestine

Question 41

What is required from the stomach to small intestine?

Answer 41

Further digestion and protection from acidic chyme (mucous and neutralise acid)

Question 42

How is mucous provided?

Answer 42

By glands in the submucosa of the duodenum

Question 43

How is acid neutralised?

Answer 43

Enzymes and bicarbonate provided by pancreas

Question 44

What is the shape of the pancreas?

Answer 44

Round head in c shaped duodenum

Question 45

Where is the tail of the pancreas?

Answer 45

To the spleen

Question 46

What is the pancreas posterior to?

Answer 46

The stomach

Question 47

What does the pancreas have a duct into?

Answer 47

The duodenal lumen (bile duct + pancreatic duct = duodenal papilla)

Question 48

Where is the pancreas found?

Answer 48

Retroperitoneal

Question 49

Where does the bile duct meet the pancreatic duct?

Answer 49

At the entrance to the hepatopancreatic ampulla

Question 50

What does the duodenal papilla do?

Answer 50

Project into the duodenal lumen

Question 51

What is release into the pancreas controlled by?

Answer 51

Hepatopancreatic sphincter

Question 52

What does endocrine mean?

Answer 52

inside, into blood

Question 53

What is the endocrine function of the pancreas?

Answer 53

Pancreatic islet alpha cells secrete glucagon and pancreatic islet beta cells secrete insulin

Question 54

What is the exocrine function of the pancreas?

Answer 54

Acinar cells secrete digestive enzymes and duct cells secrete biacrbonate

Question 55

What does exocrine mean?

Answer 55

Outside, into the GI tract

Question 56

What is the structure of pancreatic acinar cells?

Answer 56

Apical zymogen granules, basal nucleus and abundant rough ER

Question 57

What is the function of pancreatic acinar cells?

Answer 57

Secrete enzymes