Motility

Question 1

name the two nervous systems that control the GI

Answer 1

enteric and autonomic`

Question 2

name the two locations that innervation occurs in the GI tract (complexes)

Answer 2

myenteric and submucosa

Question 3

where is the myenteric complex located?

Answer 3

in between the longitudinal and circular smooth muscle

Question 4

where is the submucosal complex located?

Answer 4

below the circular muscle

Question 5

parasympathetic neurons synapse where in the GI system? two location

Answer 5

submucosal and myenteric complexes

Question 6

sympathetic neurons synapse in what two locations in the GI system?

Answer 6

either in the enteric system or directly on smooth muscle

Question 7

what are the two types of nervous system reflexes in the GI tract?

Answer 7

long and short arc

Question 8

describe a long arc GI reflex

Answer 8

mechanoreceptors sense change and go through efferent vagus and then afferent vagus causes endocrine cells to release the goods

Question 9

describe a short arc GI reflex

Answer 9

chemoreceptors sense change and go through enteric system to innervate secretory cells and tell them to release

Question 10

what is the myeneteric plexus mainly in charge of?

Answer 10

contraction

Question 11

what is the submucosal plexus mainly in charge of?

Answer 11

secretions

Question 12

cells of cajal regulate what in the GI tract?

Answer 12

they are the pacemaker cells and release slow waves at specific frequencies in different locations

Question 13

if you add a stimulatory response to the cells of cajal what happens to muscle tone and AP?

Answer 13

AP occurs and muscle tone increases

Question 14

if you add a inhibitory response to the cells of cajal what happens to muscle tone and AP?

Answer 14

muscle tone decreases and AP does not occur

Question 15

which location in the GI has the highest frequency of slow waves from the cells of cajal?

Answer 15

Duodenum

Question 16

where does mass movement peristalsis occur?

Answer 16

in the colon…shit

Question 17

where does migrating motor complex peristalsis occur and when?

Answer 17

mid stomach to SI during interdigestive phase

Question 18

what is the goal of segmentation movements?

Answer 18

mix luminal contents without moving them forward…promotes digestion and absorption

Question 19

where does segmentation occur?

Answer 19

SI and proximal colon

Question 20

what is haustration segmentation and where does it occur?

Answer 20

in the colon…is similar to segmentation but has the goal of removing water and compacting the shit

Question 21

in peristalsis…the circular muscle behind the food is contracted or relaxed? what about the longitudinal muscle?

Answer 21

circular is contracted and longitudinal is relaxed

Question 22

in peristalsis…the circular muscle ahead of the food is contracted or relaxed? what about the longitudinal muscle?

Answer 22

circular is relaxed and longitudinal is contracted

Question 23

explain how segmentation occurs

Answer 23

alternate contractions and relaxations of circular smooth muscle in different segments

Question 24

primary peristalsis in the esophagus is initiated by what?

Answer 24

swallowing

Question 25

secondary peristalsis in the esophagus is initiated by what?

Answer 25

residual food in the esophagus

Question 26

if you have decreased gastric accomodation…will you fill up faster or slower?`

Answer 26

much faster

Question 27

when there is food in the esophagus…explain how the stomach prepares for its entrance? what is the nerve response?

Answer 27

vasovagal reflex…leads to Nitric Oxide and VIP being released from enteric system and the stomach relaxing

Question 28

what two reflexes contribute to gastric accomodation once food is in the stomach?

Answer 28

enteric local reflex

vasovagal from stretching

Question 29

what is it called when food in esophagus leads to stomach relaxation?

Answer 29

receptive relaxation

Question 30

describe how the stomach contracts during digestion? where does the contraction begin? and how does the strength change?

Answer 30

begins in the body of the stomach and increases in strength as you move to the pyloric region

Question 31

name the three muscular movements of the stomach

Answer 31

propulsion
grinding
retropulsion

Question 32

where does grinding occur in the stomach?

Answer 32

in the antrum…grinds the food and pushes some into the duodenum

Question 33

what three things stimulate increased force of stomach contractions?

Answer 33

parasympathetic activity
gastrin
motilin

Question 34

what three things stimulate decreased force of stomach contractions?

Answer 34

sympathetic activity
secretin
GIP

Question 35

what type of food is quickest to exit the stomach and what type is slowest?

Answer 35

fat is slowest and glucose/carbs are fastest

Question 36

what are the two muscular ways to slow gastric emptying?

Answer 36

decrease tone of proximal stomach

decrease strength of antral contractions

Question 37

name the three molecules that cause slower stomach emptying…these are released from the SI?

Answer 37

secretin
CCK
GIP

Question 38

name the three movements of the colon

Answer 38

segmentation
haustration
mass movement peristalsis