5.2 Flashcards
what are the mechanical functions of Motility?
- Grinding
- Storage
- Mixing
- Propulsion= הנעה
- Reflux inhibition
what are the slow wave actibvity?
- Generated by interstitial cells of Cajal (btw circular to longitudinal muscle layers)
- continuous fluctuation of membrane potential
- electric activity propagates throught gap junctions
slow wave frequency
Stomach= 3/min Duodenum= 12/min
Generation of slow wave?
- VG Ca++ ch open
- AP spike (Ca++ influx)
- CA++ dependent K+ ch open
- slow Hyperpolarization
- VG Ca++ ch close
- Internal Ca++ conc descrease
- CA++ dependent K+ close
what is segmetation?
No Net movement
Main functions of oral cavity?
mastication swallowing lubrication testing teeth protection
where can we find the swallowing centers?
medulla
lower part of pons
1st Phase of swallowing (oral)
Tongue pushes bolus against soft palate and back of mouth
triggering swallowing reflex
2nd Phase of swallowing (pharyngeal)
Upper esophageal sphincter relaxes whule epiglottis closes to keep swallowed material out of the airways
3rd Phase of swallowing (esophageal)
Food moves downward into esophagus, popelled by peristaltic waves and aided by gravity
what is primary peristalsis?
continuation of the peristalsis wavw that begins in the pharynx
what is secondary peristalsis?
results from distension of the esophagus
when the LES fails to relax what is the name of the disorder?
Achalasia
stomach can store up to
1.5 L food
functions of the proximal stomach
no phasic contraction
