3.1.3 GI Hormones Flashcards Preview

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Flashcards in 3.1.3 GI Hormones Deck (35)
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1
Q

What is the oral phase of digestion?

A

mastication, starch digestion, swallow

2
Q

Describe the duodenal phase

A

most pancreatic secretions, secretin release, suppression of acid production (inhibit parietal/ECL cells)

3
Q

What is the small intestine phase?

A

absorption of nutrients and water/ions, release of peptide YY to inhibit gastric functions

4
Q

What is the esophageal phase?

A

peristalsis, relaxation of UES and LES

5
Q

Describe the duodenal regulation of pancreatic HCO3- secretions. Focus on the role of one particular enzyme and what are the stimulators

A
6
Q

What is the role of serotonin in the GI tract?

A

Modulation of intestinal motility

7
Q

What is the cephalic phase?

A

sight, small, taste, thought of food → saliva, acid, pancreatic secretions, gallbladder contractions

8
Q

Where does gastrin travel to ellicit its action?

A

travels to oxyntic mucosa to stimulate production of acid by parietal cell

Also acts on ECL cells to activate histamine, which also activates parietal cells

9
Q

Draw a chart of the gastric phase of digestion

A
10
Q

What is the role of somatostatin in the oxyntic mucosa?

A

Reduce histamine release

Reduce HCl secretion

Reduce pepsin secretion

11
Q

Gastrin producing G cells are where?

A

Antrum

12
Q

What induces gastrin secretion?

A

Antrum distension

Gastrin releasing peptide

Fat, protein and AAs

Lumen neutralization

13
Q

How does somatostatin affect insulin?

A

Inhibits it

14
Q

What are enterogastrones? What are some examples?

A

Hormones that inhibit stomach processes

Ex. CCK and secretin

15
Q

Fill in this chart.

A
16
Q

Describe the activation of pepsinogen

A

Acid in stomach stimulates local neurons and release of secretin → Chief cell stimulated by nerve (ACh) → somatostatin inhibits it

17
Q

What are suppressors of gastrin?

A

Somatostatin

Starvation

Lumen Acid less that pH3

18
Q

What is the role of the pancrease in the intestinal phase?

A
19
Q

What is the main cell type that releases pepsinogen?

A

Chief cells

20
Q

Secretin is release by what cells and is stimulated by?

A

released by S cells, activated by chyme

21
Q

What is the role of CCK on the gall bladder? Discuss the signaling pathway

A
22
Q

What are the neurotransmitters/neurohormones that alter GI motility?

A

Notice the changing role of CCK when changing from small intestine and stomach

23
Q

Gastrin releasing peptide is produced where and affects where?

A

GI nerves and effects muscle and mucosa

24
Q

Describe the colonic phase.

A

absorption of water and ions, storage and elimination of feces

25
Q

What is the gastric phase of digestion?

A

stimulated by stretching, acid secretion, pepsinogen, pancreas and gallbladder activation

26
Q

What are the important players in the negative feed back of pancreatic secretions?

A

somatostatin - produced by intestinal D cells

peptide YY - Induced by fat in distal small intestine

glucagon

Pancreatic Polypeptide - stimulated by vagus

27
Q

What is the gastric phase of digestion in regards to the pancreas, gallbladder and colon?

A
28
Q

What is the role of somatostatin in the antrum?

A

Reduce gastrin release

29
Q

What is the role of motilin?

A

Phase III interdigestive intestinal motility

30
Q

What is this an image of?

A

Enterochromaffin cell producing serotonin

31
Q

Describe the hormonal and neuronal regulation of gastric acid secretion?

A
32
Q

GLP-1 does what to gastric emptying?

A

It slows emptying

33
Q

How does histamine affect D cells?

A

Histamine will stimulate D cells to produce somatostatin, which can in turn inhibit the ECL and parietal cells

34
Q

What is the function of gastrin?

A

Stimulate parietal cell acid secretion

Stimulate histamine release

Incease tone of LES

Induce mucosal growth

Induce somatostatin release

35
Q

Describe the activation and action of CCK

A

chyme → releasing peptide by I cells → vagus signal → pancreas

Fats to duodenum → CCK release → gallbladder contraction and relaxation of sphincter of Oddi by vagus n.

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