GI Movement Flashcards
peristaltic reflex is initiated by the
ENS
Long distance propultion is prevented by
closing the transmembrane gates
what part of controls swallowing
midbrain
what is esophageal achalasia
loss of LES inhibition
what are the stomach functions
(MESS) mixing, emptying, storage, secretion
motor behavior of antral pump is generated by
gastric ICC
what is the leading contraction of the antral pump caused by
rising phase of AP
is the pyloric sphincter opened or closed on the leading contraction
closed
T/F AP in the antral trunk does not occur in the absence of any nuerotransmitter
false, it does occur
what is the affect of ACh on the amplitude of the plateau phase of antral contraction
increases amplitude
what is the effect of gastrin on the activity of the pyloric pump
stimulates
what nerotransmitters decrease the amplitude of the plateau phase and that of associated contractions
NE and VIP
what are the two primary functions of the gastric resevoir
accommodation of food, maintain compressive force (inhibited by insulin)
what is receptive relaxation
mechanoreceptors in pharynx during swallowing stimulate the vagus to inhibit musculomotor neurons, thus stretching stomach
what is the adaptive reflex
stretching of stomach causes vasovagal reflex to inhibit musculomotr neurons, stretching out stomach. this is lost in vagotomy and diabetic neuropathy
what is feedback relaxation
presence of nutrients in SI stimulate vagus to stretch, slow down
what are the characteristics that make emptying slower
high caloric content, high acidity, hyper/hypotonic, large food particles, smaller gastric emptying
duodenal factors in gastric emptying
distention, irritaion, acidity, osmolality, breakdown of proteins, hormonal feedback (GIP, CCK)
what happens in the absence of MMC
bacterial overgrowth
what is the purpose of the MMC
sweeps up the intestine
when does MMC end
ingestion
MMC relies on program of
ENS
what is the effect of the vagus nerve on MMC
inhibitory, without vagus stimulation MMC occurs
what type of relaxation allows the ascending colon to accept large volumes of chyme from ileum
adaptive
haustration is powered by
ENS
irritant laxatives stimulate
power propulsion (starts in middle of transverse colon), also gastrocolic reflex
responsible for mass movement to sigmoid colon and rectum
neural program
following a bilateral vagotamy which is lost
gastric adaptive reflex
allows ibuprofen to reach the intestine fastest
saline
defecation reflex is powered by
spinal reflex
