The stomach

Question 1

Lower oesophagus and cardia

Answer 1

Mucus, HCO3-,

prevent reflux

Question 2

Fundus and body

Answer 2

H+, intrinsic factor, mucus, HCO3-, pepsinogens, lipase

reservoir, tonic force when emptying

Question 3

Antrum and pylorus

Answer 3

Mucus, HCO3-

mixing and grinding

Question 4

Accommodation depends on stretch receptors

Answer 4

signal via vagus –> descending signals –> ENS –> relaxation –> dilation
Fundus and body–> 1 L food with no rise in pressure

Question 5

Duodenum senses delivery acid, AA and lipids

Answer 5

–> secretes hormone (ENS controls)- CCK, secretin and GIP} decrease gastric motility and emptying

Question 6

Gastric pits

Answer 6

mucous cells, HCO3-} protect epithelium

Damaged by H.pylori

Question 7

Gastric glands (oxyntic cells)

Answer 7

HCl and intrinsic factor} fundus and body

Question 8

G-cells

Answer 8

Gastrin (into blood) in atrial/ pyloric galnds

Question 9

Gastrin

Answer 9

2 forms: G17- main form in antrum & G34-main form in duodenum
receptor= CCK-B receptor
stimulated by: luminal proteins/AA, parasymapthetic- stretch response- mediated by gastrin releasing peptide from interneurons
inhibited by: pH below 3, somatostatin and GIP

Question 10

Parietal (oxyntic) - acid secretion

Answer 10

K+/H+ATPase pump–> swaps H+ for K+ –> HCl into stomach and HCO3- into blood} alkaline tide
Stimulated by: gastrin and ACh
Inhibited by: somatostatin and prostoglandins