Preparation With Complete Questions And Correct
Answers With Rationales |2026/2027| Already Graded
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Pharynx - ANSWERextends from internal nares to
esophagus (posteriorly) + larynx (anteriorly)
beginning of deglutition (swallowing) facilitated by saliva +
mucous
Esophagus - ANSWERposterior to trachea
enters mediastinum anterior to vertebrae
pierces through diaphragm at esophageal hiatus
ends at superior portion of stomach
,secretes mucous + transports food to stomach (lubes the
bolus)
4 layers of esophagus - ANSWER1) Mucosa = stratified
squamous - terminal end - mucous glands
2) Submucosa = mucous glands
3) Muscularis = upper 1/3 - skeletal, middle - mixed, lower
1/3 - smooth
4) Adventitia (outer layer) - areolar CT (connects esoph. to
other structures in mediastinum)
doesn't have serosa layer
, Sphincters of muscularis layer of esophagus -
ANSWERformed at either end
upper esophageal sphincter = skeletal muscle
lower esophageal sphincter = smooth
Deglutition stages - ANSWER1) Voluntary stage
2) Pharyngeal stage
3) Esophageal stage
Deglutition - voluntary stage - ANSWERbolus pushed into
oropharynx
, tongue moves upwards to soft palate
Deglutition - pharyngeal stage - ANSWERinvoluntary
sensory nerves send signals to deglutition center in
brainstem - soft palate = lifted to close nasopharynx
larynx = lifted and epiglottis bent to cover glottis
Deglutition - esophageal stage - ANSWERbolus enters
esoph.
upper sphincter relaxes when larynx is lifted
peristalsis - pushes food down
- circular fibers behind bolus
- longitudinal fibers in front bolus - contract and shorten
distance of travel, pull esoph. up to bolus