motility

Question 1

what are the 3 layers of muscle in the stomach

Answer 1

outer- longitudinal
circular
oblique

Question 2

what is the nerve supply of the myenteric plexus

Answer 2

p’symp via the vagus

symp via the coeliac ganglion

Question 3

what is the sensory afferent for the stomach

Answer 3

vagal and splanchnic nerves

Question 4

what are the layers of the stomach wall

Answer 4

epithelia 
mucosa
lamina propria
muscularis mucosae
submucosa
subnmucosal plexus 
muscularis externa and myenteric plexus

Question 5

what is receptive relaxation

Answer 5

distension of the lower oesophagus induces relaxation of the orad

Question 6

what is the vagovagal reflex

Answer 6

mechanoreceptors relay information to the CNS

VIP is released for vagal nerves causing orad relaxation on swallowing food or on distension of the stomach

Question 7

what are the movement patterns of the stomach

Answer 7

propulsion
grinding
retropulsion

Question 8

what is the slow wave frequency of the stomach

Answer 8

3-5 per min

Question 9

what does neural and hormonal input effect

Answer 9

action potential frequency but not slow wave frequency

Question 10

what hormones increase action potential frequency and force of contraction

Answer 10

gastrin and motilin and p’symp

Question 11

what hormone decreases action potential frequency

Answer 11

secretin and symp

Question 12

what hormone mediates migrating myoelectric complexes

Answer 12

motilin (endocrine cells)

Question 13

how often do MMCs happen

Answer 13

90 mins

Question 14

how long does it take to empty the stomach

Answer 14

3 hours

Question 15

how small must solid particles be before they are released

Answer 15

less than 1 mm3

Question 16

what hormone inhibits gastric emptying in the presence of fat

Answer 16

cholecystokinin

Question 17

what effect does protons have on gastric emptying

Answer 17

inhibits-

detected by duodenum and relayed to stomach via the myenteric plexus

Question 18

what neurotranmitters does the p’symp ns use in the intestine

Answer 18

ach and motilin via the vagus

Question 19

what neurotranmitter does the symp ns use in the intestine

Answer 19

noradrenaline via the coeliac and superior mesenteric ganglia

Question 20

what is the slow wave frequency in the duodenum

Answer 20

12

Question 21

what is the slow wave frequency in the ileum

Answer 21

9 per minute

Question 22

how are contranctions in the small intestine coordinated

Answer 22

ENS

Question 23

what hormones in the gut cause orad contraction

Answer 23

ach and substance P

Question 24

what hormones in the gut cause caudad relaxation

Answer 24

VIP and nitric oxide

Question 25

what is the p’symp supply of the colon

Answer 25

vagus up to the transvers colon

pelvic nerves for sigmoid- anal canal

Question 26

what reflexes cause mass movements in the colon

Answer 26

gastrocolic and duodenocolic

Question 27

what is the gastrocolic reflex

Answer 27

distension of the stomach increases motility in the colon

Question 28

what mediates the two limbs of the gastrocolic reflex

Answer 28

p’smyp ns - afferent

efferent- CCk and gastrin

Question 29

describe emesis

Answer 29

• Reverse peristalsis in small intestine
• Relaxation of the stomach and pylorus
• Forced inspiration to increase abdominal pressure
• Relaxation of the lower oesophageal sphincter
• Forceful expulsion of gastric and duodenal contents

Question 30

somatostatin - delta cells

Answer 30

inhibits glucagon and insulin release