GI physiology 2

Question 1

which cells secrete pepsinogen

Answer 1

chief cells

Question 2

T/F pepsinogen is NOT a zymogen. And what is a zymogen

Answer 2

F
Precursor, pepsinogen is a precursor to pepsin

Question 3

Pepsinogen IS mediated by input from _______ nervous system (ACh)
A)PARASYMPATHETIC
B)SYMPATHETIC
C) ENTERIC

Answer 3

ALL but C is what it is mediated by which is para and symp

Question 4

what type of enzyme is pepsin

Answer 4

proteolytic/protease

Question 5

T/F
Conversion of pepsinogen to pepsin is pH dependent

Answer 5

T

Question 6

what pH is optimal for conversion of pepsinogen to pepsin

Answer 6

2

Question 7

what type of feedback loop is conversion of pepsinogen to pepsin

Answer 7

positive

Question 8

what creates the optimal pH for pepsinogen conversion to pepsin

Answer 8

low pH from HCL

Question 9

what cell produces HCL for optimal pH of 2 for conversion of pepsinogen to pepsin

Answer 9

parietal

Question 10

pepsin main function

Answer 10

Pepsin breaks down dietary proteins reaching the stomach into amino acids

Question 11

what % of protein digestion does pepsin account for
A)30
B)10
C)50
D)20
E)80

Answer 11

D

Question 12

What is the aprx volume of an empty stomach

Answer 12

50 mL

Question 13

what is the aprx volume a stomach can handle while eating

Answer 13

1.5 L

Question 14

_____ muscle in the body and fundus undergoes receptive relaxation

A)smooth
B)skeletal
C)cardiac

Answer 14

A

Question 15

Receptive relaxation is mediated by _______ nervous system acting on enteric nerve plexuses

A)sympathetic
B)parasympathetic

Answer 15

B

Question 16

define receptive relaxation

Answer 16

Receptive relaxation is a reflex in which the gastric fundus dilates when food passes down the pharynx and the oesophagus.

Question 17

which nerve coordinates receptive relxation

A)vagus
B)glossopharngeal
C)abdeucean
D)phrenic

Answer 17

A

Question 18

which 2 neurotransmitters released by enteric nerves mediate receptive relaxation

Answer 18

Nitric oxide
serotonin

Question 19

what is peristalsis

Answer 19

contractive waves beginning in gastric body (weakest)

Question 20

in peristalsis where does the more powerful contractions occur

Answer 20

gastric antrum and pyloric closes as wave reaches

Question 21

function of peristalsis

Answer 21

churns and transports food

Question 22

Frequency of peristaltic waves determined by ______ _____ in muscularis propria and is constant (3/minute)

Answer 22

pacemaker cells/intersticial cells of cajal

Question 23

T/F
Interstitial cells of cajal/pacmaker cells undergo fast depol and repol

Answer 23

F
slowly repol and depol

Question 24

Gastrin is triggered by _____ and ____

Answer 24

ACh
stretch receptors

Question 25

-
-

Answer 25

-duodenal luminal fat
-duodenal osmolarity
-sympathetic neurosecretory action

Question 26

strength in peristaltic contraction is decreases by

Answer 26

-duodenal luminal pH
-parasympathetic neurosecretory action

Question 27

overfilling of duodenum by hypertonic solution causes dumping syndrome of which symptoms include

Answer 27

vomiting
bloating
cramps
diarrhoea
fatigue
weakness
sweating

Question 28

delayed gastric emptying aka

Answer 28

gastroparesis

Question 29

what do G cells make

Answer 29

Gastrin

Question 30

what cells make pepsin

Answer 30

nun