Physiology of oropharynx and esophagus

What two things occur in the oral cavity?

mechanical digestion (mastication) and enzymatic digestion (via saliva)

digestion of ___ and ____ starts in the oral cavity

starch (carbohydrates) and lipids

saliva contains ____ (what enzyme)

salivary amylase

what are the 3 salivary glands, which one produces the most saliva, and what type of saliva is produced by each?

parotid: serous

submand: mucous-serous; 70% of saliva production

subling: mucous

Saliva starts out ____ and once it is released it is ____ compared to plasma

starts isotonic and at the end its hypotonic

if the saliva comes out too fast/ production is too fast then what do we see in its makeup?

it is produced too fast for ion exchange → increased Na+ and Cl- in saliva

regulation of salivary secretion: what are 4 things that have a positive affect on the nucleii salvatorii to increase saliva production

chewing, taste, smell, and nausea

regulation of salivary secretion: what are 4 things that have a negative affect on the nucleii salvatorii to decrease saliva production

sleep, fatigue, dehydration, and atropine

What cranial nerves are involved with saliva production?

CN VII and CN IX

What are the 3 protective functions of saliva?

bicarb to neutralize acid

cooling hot food

lubrication that provides oral hygiene

what are the 3 digestive functions of saliva?

alpha-amylase: digest starches/carbs

lingual lipase: lipid digestion

lubrication of food for swallowing

what are the two enzymes in saliva and what do they initiate the digestion of?

alpha-amylase: starches/carbs

lingual lipase: lipids

saliva is always ___ to plasma

hypotonic

What is the function of the R proteins in saliva?

binds to vit B12 (cobalamin) to protect it from acid degradation in the stomach

deglutition (swallowing): describe the oral stage (include voluntary or involuntary)

mouth to oropharynx, bolus is formed, voluntary process

deglutition (swallowing): describe the pharyngeal stage (include voluntary or involuntary)

involuntary process/reflex, the soft palate acts as a valve

deglutition (swallowing): describe the esophageal stage (include voluntary or involuntary)

involuntary phase that transports food to the stomach

the medulla oblongata control the ___ stage of deglutition (swallowing)

esophageal stage

swallowing innervation: impulses are transmitted through the sensory portions of ___ and ___ nerves to the swallowing center in the _____

trigeminal (CN V) and glossopharyngeal (CN IX) → medulla oblongata

the UES and LES are normally in a ____ state, and initiation of swallow ____ both sphincters

normally contracted, swallowing relaxes them

what are the 5 layers of the enteric nervous system from internal to external?

mucosa → submucosal plexus (Meissner plexus) → circular muscle → myenteric plexus (Auerbach’s plexus) → longitudinal muscle

relaxation of the LES is mediated by what two neurotransmitters?

vasoactive intestinal peptide and NO

contraction of the LES is mediated by what two neurotransmitters?

acetylcholine and substance P

What causes difficulty swallowing mainly solid food, regurgitation, weight loss, bad breath, choking, and coughing?

Zenker’s diverticulum

true vs pseudo/false diverticulum:

has all layers of the gut wall

give example

true diverticulum → Meckel’s diverticulum

true vs pseudo/false diverticulum:

lacks the muscularis layer

give example

pseudodiverticulum → Zenker’s diverticulum

what results from failure of LES to function as a sphincter

GERD (reflux esophagitis)

what lacks in newborns and is decreased in pregnancy

LES tone lacks → increased GERD

portal hypertension can lead to what?

esophageal varices (the veins bulge out) and can lead to bleeding

What condition is this pattern from the esophageal manometry showing?

Normal

What condition is this pattern from the esophageal manometry showing?

Scleroderma

What condition is this pattern from the esophageal manometry showing?

Achalasia

What condition is this pattern from the esophageal manometry showing?

Diffuse esophageal spasm

What condition is this pattern from the esophageal manometry showing?

Pharyngeal paralysis

Failure of relaxation of the upper esophageal sphincter (UES) is most likely due to what muscle?

Cricopharyngeus

During the pharyngeal phase of swallowing, what event prevents aspiration?

Closing of the nasopharynx

A patient with Zenker diverticulum most likely has a dysfunction of what structure?

Cricopharyngeal muscle