Motility Disorders Flashcards
etiologies of GI motility disorder
CNS, neuropathic (enteric nervous system), myopathic, abnormalities in interstitial cells of Cajal
is esophagus skeletal or smooth muscle
upper = striated muscle, distal = smooth muscle
voluntary swallowing phase
chewing, bring bolus back with tongue, which raises soft palate and closes off nasopharynx
Dysphagia
difficulty swallowing/discomfort in swallowing
Achalasia
muscles in lower esophagus fail to relax and food can’t get into stomach
Scleroderma
multisystem disorder with obliterative small vessel vasculitis and connective tissue proliferation with fibrosis of multiple organs
Main pathologic abnormalities of GI tract in sclertoderma
smooth muscle atrophy and gut wall fibrosis
Esophageal manifestations of scleroderma
smooth muscle atrophy can cause weak peristalsis –> dysphagia
- can also cause weak LES –> GERD
- unrepentant gerd can lead to esophagitis and stricture
is smooth muscle atrophy and gut wall fibrosis myopathic or neuropathic
MYOPATHIC
how to diagnose esophageal disease
Esophageal manometry (transnasal probe)
Main characteristic of scleroderma patients
PERISTALSIS ABSENT due to atrophy of smooth muscle and weak LES
Main characteristic of spastic disorders of esophagus
PERISTALSIS PRESERVED!!
symptoms of spastic disorders of esophagus
chest pain, dysphagia
postulated pathophys of spastic disorders of esophagus
overactive excitatory nerves (neuropathic) or overreacting smooth muscle response (myopathic)
how are inhibitory nerves distributed in esophagus
fewer proximal and more as you go distal
Jackhammer esophagus
hypercontractile; contractions coordinated but excessive amplitlude
2 main ideas of stomach motility
retropulsion and receptive relaxation
Receptive relaxation
vagally-mediated inhibition of smooth muscle tone of stomach body–maintain low intragastric pressure
what drives liquid emptying
tonic pressure gradient
what drives solid emptying from stomach
vagall-mediated contractions and enteric nervous system
how are residual solids emptied
migrating motor complex every 90-120 minutes
what causes retropulsion
mixing/churning of stomach tries to push food contents along but pyloric sphincter only opens so much/too big of particles get retropulsed back for more digestion
Gastric reservoir function
receptive relaxation and accomodation
gastric accommodation
stomach likes to keep things low pressure, so smooth muscle relaxation due to mechanical distention (gastric mechanoreception from enteric nervous system); vasovagal response