GI motility

Question 1

what are extrinsic nerves of GI (2)

Answer 1

1. symp

2. para

Question 2

what are intrinsic GI nerves

Answer 2

enteric system

Question 3

how is muscle of esoph different

Answer 3

striated for first 1/3 then transition to smooth later

Question 4

where is myenteric plexus

Answer 4

nerve plexus b/x muscle layers in GI responsible for muscle control

Question 5

what does symp activation do

Answer 5

lower peristalsis and incr. anal tone

Question 6

what is pacemaker of enteric system

Answer 6

ICC - interstitial cells of colal

Question 7

what transmitters inhib and excite SMC

Answer 7

NO, VIP - relax

Ach - excit

Question 8

what causes action potential im SMC

Answer 8

influx of Ca

Question 9

what make SMC slow wave

Answer 9

slow repolarization

Question 10

what is channel on smooth muscle and what does it mean

Answer 10

voltage-sensitive (L-type) Ca channel

- means needs to hit specific voltage threshold and also is long repolarization type

Question 11

2 parts of SMC coupling

Answer 11

1. slow wave

2. action potential (spike)

Question 12

function of slow wave

Answer 12

omnipresent, produces weak contractions, set basic rhythm

Question 13

function of spikes

Answer 13

on top of slow waves, force of contraction based on number and amp of spikes

Question 14

3 types of esoph. peristalisis and what

Answer 14

1. primary - init by swallow - all along esoph
2. secondary - init by local distension- all along SMC portion
3. tertiary - spontaneous in distal - clearance - often dysfunctional

Question 15

3 things to diff. in oropharyngeal vs. esophageal dysphagia

Answer 15

1. init of swallow
2. choking/cough
3. location of holdup

Question 16

4 ways to differentiatie b/w dysmotility and obstruction

Answer 16

1. inermittent vs. persisitent and progressive
2. liquid and solid vs. solid only
3. temp/stress vs. bread meat
4. assoc. medical illnesses

Question 17

5 alarm signs in dysphagia (cancer)

Answer 17

1. rapid progression and weight loss
2. bleeding
3. vomiting
4. odynophagia
5. age

Question 18

2 types of mechanical lesion

Answer 18

1. intrinsic - CA, diverticula, stricture, rings

2. extrinsic - large aorta, mediastinal mass

Question 19

3 motor functions of somach

Answer 19

1. take in food (relax)
2. trituration - much up food
3. emptying into pyloris

Question 20

how is peristalsis initiated

Answer 20

1. local distension leads to asc. exitation (ach) and descending relaxation (NO)

Question 21

what are 3 phases of contraction

Answer 21

1. irregular during eating
2. quescent contraction when fasting
3. housekeeping push through every 1.5 hours wehn fasting

Question 22

3 phases of colonic peris

Answer 22

1. early segmenting, non-peristalsis to slow fecal stream and absorb water
2. transverse - occasional to push stool forward
3. desceding - rare mass movement

Question 23

3 conceptual types of constipation

Answer 23

1, not enough content

2. not moving
3. not coming out