Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

33 Cards in this Set

  • Front
  • Back
3 major tissue layers in GI tract
muscularis externa
componants of mucosa
Epithelial (squamous in esophagus, columnar in SI)
Lamina Propria
Muscularus Mucosa
purpose & composition of lamina propria
maintain epi layer (like basement membrane)
collagen & elastin
purpose of muscularis mucosa
maintain structure lamina propria (folds & ridges)
components of submucosa
collagen & elastin
nerves, vessels & glands
purpose & components of muscularis externa
inner is circular
outer is longitudinal
smooth muscle communicates via ...
gap junctions:
connexins form connexons
2 connexons line up & form ion channel
composition of serosa
simple squamous epithelium
6 sphincters in GI tract
UES, LES, Pyloric, Ileocecal, EAS, IAS
esophageal peristalsis
primary & secondary
circular then longitudinal ctx
8-10 s (or 5-8 upright)
LES relaxes ...
at initiation of swallow
Phase shift
amplitude of wave "travels" along length of tube
patient presents with:
dysphagia, belching, regurgitation of undigested food, minimal reflux
barium eval with "beak like projection" & distended esophagus
Achalasia results from
degeneration of ganglion in muscular layers
treatment for achalasia
pneumatic dilation (3% risk of rupture, 75% get relief)
botox (60% with relief at 1 year)
Mechanism of botox
Synaptotagmin (R) recognizes heavy chain
Light chain is metalloproteinase (toxin)
LC cleaves SNAP 25 and ___________
Can't fuse with membrane protein to allow ACh into terminal
diffuse esophageal spasm
uncoordinated peristalsis but LES with ability to relax
2 actions of stomach
mix food with secretions
push into intestines
muscle involved in mechanical digestion in GIT
oblique muscle layer (innermost) of stomach
normal epithelials of esophagus transformed into columnar
Barett's esophagus
progression of Barett's
Barett's changes
with low grade dysplasia
with high grade dysplasia
control of gastric emptying
at pyloric sphincter
size dependent (dog experiment with liver & spheres)
pressures in stomach
amplitude increases from fundus to pyloric sphincter
phase shift
electrical activity in stomach
little depolarization at top, increases as go down
Slow wave potential
5/minute stomach
12/minute in SI
maintains potential near threshold
characteristics of small intestine motility
slow wave potential segmentation
"mixing" in SI, circular smooth muscle
characteristics of large intestine motility
Haustral contractions
Mass movements
triangular units, slow to develop to relax, mix & remove fluid
Haustral contractions (LI)
1-3 x per day
propulsion in LI
series contractions lasting 10-30 min
Mass movements (Haustral ctx cease)
passage from SI to LI
at ileocecal sphincter
ileal distention, sphincter relaxes, colonic pressure causes feedback to tighten sphincter
effect of mass movement at rectum
rectum contracts
IAS relaxes
EAS gets spike in electrical activity
conscious decision to relax or contract EAS