GI ML: 3 Flashcards
What two processes of the GI Tract are in the mouth
motility and secretion
Motility in the mouth
chewing (mastication)
What is mastication
grind food to increase SA
-mix with saliva to aid tatse
What is the secretion in the mouth
saliva from three pairs of salivary glands
What makes up saliva
water
mucus
bicarb- neutralizes acids in food and bacterial metabolites
lysozyme- kills bacteria to maintain health
amylase- breaks down plysaccrides
lipase- digestion of triglcyerides
What does the parasymp do to saliva
lots, thin, watery
what does the symp do to saliva
little, thick, and viscous
What phase occurs in the pharynx
motility- second motilary which is swallowing
What is the first phase of swallowing
oropharyngeal phase
What happens during the oropharyngeal phase
- voluntary elevation of lips and mandilble propels food to back of oral cavity
-involuntary elevation of uvula and soft palate to prevent food from going into nasal cavity
-larynx elevates, bolus flattens, and epiglottic covers glottis
-UES opens (smooth muscle relaxes)
-UES closes rapidly to prevent excess gas
What is the second phase of swallowing
esophageal phase
What happens during the esophageal phase
-food moves down the esophagus
-peristaltic wave
-5-9 seconds
-LES “cardiac” opens and bolus enters stomach
How is the propulsion regulated in the esophageal phase
the brain
How are the 1 and 2nd round of peristaltic wave connected
the 1 round is stretch detected by mechanorecpetors which then triggers 2nd wave which is a lot stronger
What part of the esphagus is skeletal
the first 1/3
