GI Physiology Overview

Question 1

Eructation?

Answer 1

Burp

Question 2

Borborygmi?

Answer 2

Rumbly tumbly

Question 3

Voluntary sphincters?

Answer 3

UES and External Anal

Question 4

Mucus produced by what type of cells?

Answer 4

Goblet

Question 5

Bile salts recycled via what process?

Answer 5

Enterohepatic circulation

Question 6

Breakdown of Liver blood supply hepatic portal vein vs. hepatic artery?

Answer 6

3/4 portal vein

1/4 hepatic artery

Question 7

Where is most H2O reabsorbed?

Answer 7

S intestine

Question 8

Phasic vs. Tonic Contractions?

Answer 8

Phasic = fast
Tonic = Slow

Question 9

Where is tonic contraction most important?

Answer 9

at the sphincters

Question 10

What part of a slow wave is influenced by Ca channel opening?

Answer 10

AMPLITUDE not frequency of wave

Question 11

What type of signal and what NT cause an increase in amplitude of the slow wave?

Answer 11

Parasympathetic release of ACh

Question 12

Peristaltic contractions vs Segmental contractions?

Answer 12

Peristaltic = propulsion found in esophagus
Segmental = circular found in S and L intestines

Question 13

What state activates the Migrating Motor Complex? What hormone?

Answer 13

Fasting state release of motilin

Question 14

What is the Migrating Motor Complex?

Answer 14

Relaxation of the sphincters paired with SM contraction to clear GI system

Question 15

Where is the submucosal nerve plexus located?

Answer 15

around the S and L intestine

Question 16

What layers is the myenteric nerve plexus located?

Answer 16

Circular and Longitudinal SM layers

Question 17

What NT can stimulate myenteric nerve plexus and is released by enterochromaffin cells?

Answer 17

5HT

Question 18

What is the Vago-vagal reflex?

Answer 18

Reflux of both afferent and efferent fibers in the vagal nerve control peristaltic motion

Question 19

ACh effect on GI system?

Answer 19

SM contraction
Increased Ca
Increased Secretions

Question 20

Gastrin Release Peptide effect?

Answer 20

G Cell release of gastrin

Question 21

Substance P effect?

Answer 21

Same as ACh

Question 22

Vasoactive Intestinal Peptide (VIP) effect?

Answer 22

Increased Motility
SM relaxation
Increases Secretion

Question 23

NO effect?

Answer 23

Same as VIP

Question 24

Gastrin effect? On what cell?

Answer 24

Parietal cell increased HCl secretion

Increased Pepsinogen release

Question 25

CCK released by what cell?

Answer 25

I Cell

Question 26

CCK does what in response to what?

Answer 26

Fat and AA detection

Increases Pancreatic secretion and Bile Salt release

Question 27

Secretin released by what cell?

Answer 27

S Cell

Question 28

Secretin does what in response to waht?

Answer 28

High H+

Increases Pancreatic secretion and HCO3- release

Question 29

Gastric Inhibitory peptide secreted by what cell?

Answer 29

K Cell

Question 30

GIP does what in response to what?

Answer 30

Carb and fat detection

Decreases Gastrin, Increases Insulin release

Question 31

Paracrine molecules?

What cells?

Answer 31

Histamine from ECL cells

Somatostatin from D Cells

Question 32

Histamine does what?

Answer 32

Increases D Cell (somatostatin)

Increases Parietal Cell (HCl)

Question 33

Somatostatin does what?

Answer 33

INHIBITS

• Histamine
• H+
• Gastrin

Question 34

Mesenteric Ischemia caused by?

Answer 34

Emboli

Reflex vasoconstriction

Question 35

Bacterial overgrowth syndrome symptoms? (4)

What causes the symptoms?

Answer 35

Gas and bloating = Fermentation
Anemia = B12 competition
Steatorrhea = Deconjugation of Bile Acids
Epithelial damage = Toxin release

Question 36

DX for bacterial overgrowth syndrome?

Answer 36

Breath test