Gastro 3 - Stomach

Question 1

What are the three main arteries that come off anteriorly from the abdominal aorta?

Answer 1

Celiac trunk. Superior mesenteric artery (SMA). Inferior mesenteric artery (IMA).

Question 2

What structures does the celiac trunk supplies blood to?

Answer 2

Foregut and upper visceras: stomach, upper part of the duodenum, liver, gallbladder, pancreas, spleen.

Question 3

What structures does the superior mesenteric artery supplies blood to?

Answer 3

Everything derived from the midgut; second to forth part of the duodenum to 2/3 of the anterior part of the transverse colon.

Question 4

What structures does the inferior mesenteric artery supplies blood to?

Answer 4

Everything derived from the hindgut; distal third of the transverse colon to upper portion of the rectum.

Question 5

What is a watershed area? What are it’s strengths and weaknesses?

Answer 5

An area where it receives blood supply from two different arteries; splenic flexture. Won’t infarct when one artery is occluded but will be the first to be affected in severe hypotension.

Question 6

What are the three arteries that are coming off from the celiac trunk?

Answer 6

Common hepatic artery. Splenic Artery. Left gastric artery.

Question 7

What are the three arteries that are coming off from the common hepatic artery?

Answer 7

Gastroduodenal artery. Right gastric artery. Proper hepatic artery.

Question 8

What are the two arteries that come off the gastroduodenal artery and what path do they follow?

Answer 8

Right gastro-omental artery: Follows the greater curvature of the stomach where it anastomoses with the left gastro-omentanl artery (that comes off from the splenic artery). Anterior superior pancreaticoduodenal artery: supplies the anterior head of the pancreas, and the proximal duodenum.

Question 9

Which cells in the stomach secrete Gastric acid?

Answer 9

Parietal cells.

Question 10

Which cells in the stomach secrete pepsin?

Answer 10

Chief cells.

Question 11

Which cells in the stomach secrete bicarbonate?

Answer 11

Mucosal cells.

Question 12

What cells in the GI secrete bicarbonate?

Answer 12

Brunner glands in the duodenum. Mucosal cells in the stomach. Salivary glands. Ducts of the pancreas.

Question 13

Which cells in the stomach secrete intrinsic factor?

Answer 13

Parietal cells,.

Question 14

Which cells in the stomach secrete gastrin?

Answer 14

G cells in the antrum of the stomach.

Question 15

What does Gastrin do?

Answer 15

Stimulates acid secretion. Stimulates growth of the gastric mucosa. Stimulates gastric motility.

Question 16

What are three things that can stimulate gastrin secretion?

Answer 16

Phenylalanine. Tryptophan. Calcium.

Question 17

What regulates stomach acid secretion?

Answer 17

Gastrin. Vagus nerve.

Question 18

How does the vagus stimulate acid secretion?

Answer 18

Directly, by stimulating parietal cells. Indirectly, by stimulating G cells with Gastrin releasing peptide (GRP); Gastrin in turn stimulates parietal cells to make gastric acid and stimulates ECL (enterochromaffin-like) cells to secrete histamine (histamine-2 receptors stimulates parietal cells).

Question 19

What are some H2 blockers?

Answer 19

Cimetidine. Ranitidine. Famotidine.

Question 20

What hormones inhibit gastric secretion?

Answer 20

Prostaglandins. Somatostatins.

Question 21

What ion is exchanged for hydrogen in the lumen of the stomach?

Answer 21

Potassium.

Question 22

What is Zollinger-Ellison syndrome?

Answer 22

A Gastrin-secreting tumor (gastrinoma). Leads to recurrent duodenal ulcers. Can be related to MEN I syndrome.

Question 23

What receptors found on gastric parietal cells regulate acid secretion?

Answer 23

H2 receptors. CCK^B receptors. M3 receptors. Prostaglandin receptors. Somatostatin receptors.

Question 24

What happens to serum pH at the time of gastric acid secretion?

Answer 24

Serum pH rises because you are pumping bicarbonate to the serum.