Control Of Gut Hormones

Question 1

What are the 3 types of hormones in the GI tract based on their method of transmission?

Answer 1

Endocrine
Neurocrine
Paracrine

Question 2

What are endocrine hormones?

Answer 2

Hormones that are released into the bloodstream

Question 3

What are Paracrine hormones?

Answer 3

Hormones that act locally and dont enter the bloodstream diffusing to nearby cells or tissues

Question 4

What are neurocrine hormones?

Answer 4

Hormones released by postganglionic fibres

Question 5

What are the cells responsible for releasing hormone in repsonse to stimuli in the GI tract?

Answer 5

Enteroendocrine cells

Question 6

What are the 2 main families of hormones involved in the GI tract?

Answer 6

Gastrin family
Secretin family

Question 7

What are the 2 hormones in the Gastrin family in the GI tract?

Answer 7

Gastrin
Choleocystokinin

Question 8

What cells produce Gastrin?

Answer 8

G cells

Question 9

Where are G cells located?

Answer 9

Antrum of stomach

Question 10

What is the role of Gastrin?

When is it produced?

Answer 10

Stimulates parietal cells to release stomach acid

It’s produced when proteins are broken down in the stomach
When stimulated by the vagus nerve and stretch receptors in the stomach

Question 11

What cells produce cholecystokinin?

Where are these cells located?

Answer 11

I cells

I cells found in the duodenum and jejunum

Question 12

What is the function of cholecystokinin?

Answer 12

Contracts the gallbladder forcing bile into the duodenum

Stimulates pancreas to release digestive enzymes

Relaxes sphincter of Oddi

Question 13

What is the Sphincter of Oddi?

What is the importance of it relaxing when cholecystokinin is produced?

Answer 13

Sphincter that’s between the bile duct, pancreatic duct and the duodenum

When released allows bile from the bile duct and pancreatic enzymes to enter into the duodenum

Question 14

What type of hormones are all of the hormones in the GI system?

Answer 14

Peptide hormones

Question 15

What are hormones in the secretin family?

Answer 15

Secretin
Gastric inhibitory polypeptide

Question 16

What cells produce secretin?

Where are these cells found?

Answer 16

S cells

In the duodenum

Question 17

When do S cells produce secretin?

Answer 17

When pH is low in the duodenum

Question 18

What does Secretin do?

Answer 18

Stimulates biliary strength and pancreas to secrete bicarbonate neutralising the acidic chyme

Question 19

Where are the cell that produce Gastric inhibitory polypeptide found?

Answer 19

Duodenum and jejunum

Question 20

What stimulates the production of Gastric Inhibitory Polypeptide?

Answer 20

Stimulate by all major food groups, sugars, amino acids and fatty acids

Question 21

What is the role of Gastric Inhibitory Polypeptide?

Answer 21

Increases insulin
Decreases gastric acid

Question 22

What cell produces somatostatin?

Answer 22

D cells

Question 23

When do D cells produce somatostatin?

Answer 23

When theres a low pH in the stomach

Question 24

What is the role of somatostatin?

Answer 24

Inhibits release of Gastrin by G cells preventing production of gastric acid

Question 25

What type of hormone is somatostatin in terms of its release?

Answer 25

Paracrine

Question 26

What type of hormone is Gastrin-Releasing peptide in terms of its release?

Answer 26

Neuropeptide

Question 27

What is the role of Gastrin-releasing peptide?

Answer 27

Stimulate G cells to make Gastrin which then stimulates parietal cells to release stomach