Motility In The Intestine

cgeorge's version from 2016-02-22 16:50


Question Answer
Large intestine is made up ofAscendine, descending and transvers colon
Small intestine is made up ofDuodenum, jejunum ,ileum
Function of nonpropulsive movements?Increases mixing
Function of propulsive movements?Results in elimination of non digested material
Explain mixing in SIMixing of chyme from stomach with secretions from pancreas,liver and intestine
3 Types of motility in the SI in the FED state1) Rythmic phasic contractions 2) Segmentation 3) Peristalsis
Segmentation function:Mixing
Type of motility in the FASTING stageMigrating motor complex, regulated by motilin
Functions of migrating motor complex;1) Clear SI of residual content e.g. undigested food/desquamated cells 2) Stops colonic bacteria from migrating into the terminal ileum
Feeding ends the ... and inititates ... & ...Migrating motor complex ... segmentation ... peristalsis
Motilin is synthesiszed in Duodenal mucosa
Motilin & Somatosatin stimulateSmooth muscle contraction
Vasoactive intestinal peptide causesrelaxation
Myogenic reflex causes contraction cusStretch produces a reflex contraction mediated by opening of Ca channels
Explain gastroileal reflexIncreased gastric activity causes increased motility in the ileum & increased movement of chyme through the ileoceacal sphincter
Explain ileogastric reflexIleal distension leads to decreased gastric motility
What seperates the ileum from the colon (small from large)Ileocaecal sphincter
What causes relaxation of the sphincterStimuli proximal to the sphincter
Distension of the ileum ... the ileocaecal sphincterRelaxes
Distesion of the proximal colon causes... Of the ileocaecal sphincterContraction
Is there villi in the colon?No
Functions of the colon1) Absorb fluids 2) Regulate release of faecal material 3) Provide environment for beneficial bacteria which synthesise vitamins 4) Secretes mucous and ions
Site of absorption and bacterial fermentation occurs at proximal or distal colon?Proximal
Site of storage is the proximal colon or distal?Distal
Function of rhythmic phasic contractionsAll about mixing and trying to absorb water and nutrients from the chyme
Function of colonic giant migrating contractionsMove faecal matter towards the rectum.
Colonic giant migrating contractions occur in the fed or fasted stage?BOTH
Laxatives based aroud fibreBulk laxatives
Laxatives that soften faecesEmollient
Saline laxatives work byCreates hypertonic environemnt in the lumen of bowel. Drawing water into the lumen of the bowel
Innervation of ascending & transverse colon is viaBranches of the vagus nerve from the cervical spinal cord
Innervation of descending colon & rectum is viaPelvic nerves from the sacral spinal cord
Stimulating cervical outflow results in Rhythmic phasic contractions
Stimulating sacral outflow results in Colonic giant migrating contractions invovled in propulsion
Circular involuntary smooth muscle makes up the internal or external anal sphinter?Internal
Striated voluntary muscle makes up the internal or external anal sphincter?External