GI Motility

Question 0

peristalsis process

Answer 0

food in one region
relaxation of anal region
contraction of region with food
food propelled on (moves to area of lower pressure)
usu travels some distance along gut

Question 1

peristalsis definition

Answer 1

propulsive motility of the gut, move food or chyme from one place to another
requres NO

Question 2

mixing motion definition

Answer 2

mix secretions with food. not as neatly coordinated. localized contraction, no relaxation

Question 3

mixing motions - process

Answer 3

presence of chemicals and food
contraction of region
chyme move to either side
with relaxation, chyme is mixed.

Question 4

Mouth - mixing

Answer 4

mastication

Question 5

mouth - propulsion

Answer 5

swallowing

Question 6

mastication

Answer 6

chewing. unclear neural origin, not required for complete digestion

Question 7

Swallowing - Stage 1

Answer 7

Buccal phase - coluntary

under voluntary control. tongue rolls food back to entrance of pharynx. tongue along roof of mouth from front to back

Question 8

Swallowing - Stage 2

Answer 8

Pharyngeal phase
bolus of food stimulates afferents, synapse in NTS
controlled at reflex level. can take all sensory information and produce these actions
close nasopharynx, create channel for bolos
block trachea

Question 9

Strokes and swallowing

Answer 9

strokes that damage NTS, have a patient with stroke, make sure they can swallow.

Question 10

cough produced when swallowing wrong

Answer 10

produced by larynx= protective

Question 11

Swallowing - Stage 3

Answer 11

Esophageal phase
presence of bolus in esophagus initiates peristalsis. food enters stomach mostly through gravity. peristalsis is clean up
primary peristaliss initiated by swallow, second to clean up debris

Question 12

Motility of Stomach

Answer 12

peristalsis

under some conditions known as pyloric pump

Question 13

Mixing in stomach

Answer 13

retropulsion (variant of peristalsis)

Question 14

Peristalsis in Stomach

Answer 14

peristatltic waves travel down stomach and food moves relatively slowly.
pyloric pressure high, only liquid gets through pyloric valve.

Question 15

Retropulsion in the stomach

Answer 15

peristaltic wave travels down stomach, peristaltic wave travels faster than chyme. most chime cant leave, turns back

Question 16

Pyloric pump

Answer 16

stronger waves of peristalsis force chyme through pyloric sphincter,

Question 17

Factors increasing Gastric emptying

Answer 17

“food here, get out”
comes from stomach
1. Stretch of gastric wall, vagal and myenteric reflex
2. Gastrin (increases production of gastric acid and motility)

Question 18

Factors decreasing gastric emptying

Answer 18

arise from duodenum “wait I’m not ready”
make sure stomach doesnt dump food into SI too fast

1. enterogastric reflex. distension, acid osmolarity proteins in duodenum, –>decrease gastric motility, increase pyloric tone
2. Hormones - CCKPZ, Secretin –> increase mixing, decrease emptying

Question 19

Small Intestine Mixing

Answer 19

Segmentation

Question 20

Small intestine propulsion

Answer 20

peristalsis, with major purpose to distribute chyme for absorption

Question 21

SI Segmentation

Answer 21

Mixing, may occur in groups, singly. requires background excitation from myenteric plexus

Question 22

SI peristalsis

Answer 22

Frequency varies in different regions. faster in duodenum than ileum.
functions= move chyme to colon, spread chyme evenly.
travels about 5 cm before dying out

Question 23

Neural Control of SI peristalsis

Answer 23

gastro enteric reflex,

local and CNS effects

Question 24

Hormonal control of SI in peristalsis

Answer 24

Increase motility= gastrin, CCKPZ, insulin
decrrreased motilty= secretin and glucagon (released when acid enters duodenum. need to miz acid with pancreatic bicarb. dont want to push food past sphincter of oddi)

Question 25

Peristaltic Rush

Answer 25

irritation in SI
increase peristaltic event
clears SI of irritenat = diarrhea

Question 26

Migrating Motor Complex

Answer 26

during fasting, longer you go between meals, stronger these get
matches motilin
starts in stomach, of moderate strenght,
appears to move secretions through intestine. prevents enzymes from acting on damaging mucosa

Question 27

Ileocecal valve

Answer 27

prevents bacflow, LI has different bacteria in ith that cause problems when there is backflow

Question 28

Ileocecal sphincter

Answer 28

thickening of circular m. control entrance of chyme. normally mildly contracted

Question 29

relaxation of ileocecal sphincter

Answer 29

gastric reflex (food in stomach causes ileum to relax, including sphincter)
gastrin

Question 30

Contraction of ileocecal sphincter

Answer 30

irritation

distention of the cecum (arises from the colon)

Question 31

Mixing of colon

Answer 31

haustrations

Question 32

propulsion of colon

Answer 32

mass movement

Question 33

Haustrations

Answer 33

like sementation. strong contractions bc fecal material is becoming solid
mixing, triggered by chyme
near complete occlusion of lumen
absorb H2O,
mix HCO3 to counter acids secreted by bacteria

Question 34

Mass Movement

Answer 34

propulsive motion. travels more than 20 cm
repeats every 10-30 min until defacation
initiatied by 
gastrocolic reflex
duodenalcolic reflex
parasympathetic

Question 35

Defacation - part 1

Answer 35

local reflex.
distension. not strong, not enough to expel fecal matter
sensory motor enteric nervous system.

Question 36

Defacation part 2

Answer 36

parasympathetic
distension
receptor in gut
stronger
part 1 and 2 are strong enough for expulsion if EAS is relaxed.

Question 37

Defacation part 3

Answer 37

voluntary muscle to relax the EAS