B3 Hormones and cells

Question 1

Inhibits gastric acid secretion of parietal cells

Answer 1

Serotonin- enteroendocrine cells in the small intestine
Secretin- produced by S cells in the duodenum
Cholecystokinin- produced by endocrine cells of the duodenum
Somatostatin- via D cells of the stomach

Question 2

Produces gastrin

Answer 2

Enteroendocrine cells/ G cells in the pyloric antrum, duodenum and pancreas. Stimulated by increased gastric pH, eating peptides and amino acids and gastric distention.

Question 3

Produced by D cells in the stomach and duodenum to inhibit gastric acid secretion and stomach distention

Answer 3

Somatostatin

Question 4

Exudation of HCO3- into the blood and CL- into the cell which causes blood pH increases

Answer 4

Alkaline tide. This occurs to regulate the intracellular pH of the parietal cell during gastric acid secretion and results in a temporary increase of blood pH v

Question 5

Misoprostol

Answer 5

Prostaglandin mimetic which stimulates mucus production

Question 6

Gastric enteroendocrine cells

Answer 6

G cells

Question 7

Cells which release gastrin

Answer 7

G cells. Gastrin binds to parietal cells in the stomach body and pyloric antrum via CCK2 receptor

Question 8

What happens following gastrin binding to CCK2 receptor?

Answer 8

Activates Protein kinase -> phospholipase C to free Ca2+ stores

Question 9

What does gastrin stimulate?

Answer 9

Release of histamine from enterochromaffin-like cells, Release of acetylcholine from neurons, and it acts directly on CCK2 receptors on parietal cells for indirect activation of the H+/K+ ATPase pump.

Question 10

What activates the proton H+/K+ATPase pump?

Answer 10

cAMP
Histamine via binding to HT2 receptors for cAMP production to activate phospholipase C

Ca2+
Acetylcholine via binding to M3 receptors
Gastrin via binding to CCK2 receptors

Question 11

Vasoactive intestinal peptide

Answer 11

Causes vasodilation of smooth muscle to relax and inhibit gastrin release and prevent peristalsis

Question 12

Causes vasoactive intestinal peptide to be released

Answer 12

Gut distention

Question 13

Released following food intake and stimulates insulin release and inhibits gastric acid release

Answer 13

Glucose-dependent insulinotropic peptide

Question 14

What causes Ca2+ influx into the cells?

Answer 14

M3 activation via acetylcholine release from neurons and CCK2 receptor activation via gastrin. Protein kinase activates phospholipase C to release stores.

Question 15

H2 activation

Answer 15

Gastrin binds to enterochromaffin-like cells and causes release of histamine to bind to parietal cells and cause cAMP release

Question 16

H2 receptors

Answer 16

Stomach parietal cells

Question 17

Vomiting centre

Answer 17

Chemoreceptor trigger zone in the medulla. which lies outside the blood-brain barrier. It is stimulated by dopamine, serotonin, acetylcholine and substance P.

Question 18

What causes gastric ulcers?

Answer 18

NSAIDs and helicobacter pylori

Question 19

Anti-emetic drug

Answer 19

Histamine receptor antagonist, serotenergic antagonist, muscarinic antagonist, anti-dopaminergic

Question 20

What causes cleavage of trypsinogen?

Answer 20

Enterokinase, found in the small intestine

Question 21

What molecule causes cleavage of dipeptidases?

Answer 21

Trypsinogen

Question 22

Where does digestion of fats and proteins occur?

Answer 22

Duodenum

Question 23

What occurs in the jejunum?

Answer 23

Continues digestion of fats and proteins and start of absorption of nutrients such as iron

Question 24

What happens in the ileum?

Answer 24

Majority of absorption of B12 and nutrients like of amino acids, lipids, monosaccharides, drugs and water

Question 25

Anaemia due to lack of B12/folic acid

Answer 25

Megaloblastic anaemia (large RBC)

Question 26

Pernicious anaemia cause

Answer 26

Autoimmune disease which targets the parietal cells

Question 27

Which cells are present in the pyloric antrum?

Answer 27

G cells

Question 28

Which cells are present in the cardiac region?

Answer 28

Chief cells