Lecture 33 - Swallowing and Esophagus

Question 1

the autonomic nervous system innervates organs with _____ functions

Answer 1

involuntary

Question 2

what are the 3 distinct regions of the autonomic system

Answer 2

1. sympathetic
2. parasympathetic
3. enteric

Question 3

what are the 3 phases of swallowing

Answer 3

1. oropharyngeal
2. esophageal
3. gastroesophageal

Question 4

summarize the oropharyngeal phase of swallowing in 6 steps

Answer 4

1. oral - voluntary food prehension
2. mastication
3. formation of food bolus at base of tongue
4. bolus propelled into oropharynx
5. pharyngeal muscle contracts to transfer bolus to upper esophageal sphincter
6. muscles relax and bolus enters esophagus

Question 5

summarize the esophageal phase of swallowing

Answer 5

1. food is moved away from the oral cavity via peristalsis

primary = initiated by swallowing
secondary = distention of esophageal lumen

Question 6

summarize the gastroesophageal phase of swallowing

Answer 6

1. lower esophageal sphincter relaxes
2. food passes to stomach

Question 7

define dysphagia

Answer 7

difficulty swallowing

Question 8

what 3 “failures” can induce dysphagia

Answer 8

1. failure to chew/make bolus
2. failure for pharyngeal mm. to contract
3. failure of the cricopharyngeal to relax or contract

Question 9

what provides motor innervation to the pharynx

Answer 9

vagus nerve

Question 10

what provides sensory innervation to the pharynx

Answer 10

glossopharyngeal n.

Question 11

what nerves aid in swallowing

Answer 11

Trigeminal, Facial, and Hypoglossal

Question 12

what are the 4 clinical signs of dysphagia

Answer 12

1. hypersalivation
2. gagging
3. repeated swallowing attempts
4. dropping feed/water

Question 13

what are the functions of the esophagus

Answer 13

1. transport ingesta
2. eructation
3. egestion
4. rumination
5. regurgitation

Question 14

what is the histology of esophageal epithelium

Answer 14

stratified squamous
protection against abrasive material

Question 15

rank the skeletal mm. content in the esophagus of different species from most to least

human
dog, ruminant
cat, horse, pig

Answer 15

dog, ruminant
cat, horse, pig
human

Question 16

what are the 3 ways the esophagus can be visualized

Answer 16

1. radiographs
2. barium (contrast) swallow
3. endoscopy

Question 17

what are the 3 most common sites for esophageal obstruction? why do they occur here?

Answer 17

1. thoracic inlet
2. heart base
3. diaphragm

these are the narrowest regions of the esophagus

Question 18

the primary peristaltic wave is initiated by

Answer 18

swallowing, relaxation of LES/gastric fundus

Question 19

the secondary peristaltic wave is initiated by

Answer 19

distention

Question 20

T/F: efferent sensory input from the distal esophagus can alter motility

Answer 20

FALSE - afferent

Question 21

GRED

Answer 21

gastroesophageal reflex of acid, pepsin, and bile into the esophagus

Question 22

how is GRED treated

Answer 22

1. feeding low-fat diet
2. administer pro-motility drugs
3. administer proton- pump inhibitor to block secretion

Question 23

what is the towel test

Answer 23

feeding barium and using a towel to apply pressure around stomach/abdomen to test the integrity of the lower esophageal sphincter

Question 24

what is the lower esophageal sphincter

Answer 24

physiologic high pressure zone created by gastric mucosal folds at the right crus of the diaphragm

Question 25

regurgitation

Answer 25

spontaneous expulsion of content from the esophagus due to body position and gravity

+/- gag reflex
copious saliva

Question 26

what is a Bailey chair

Answer 26

allows dogs to remain in an upright position if they have megaesophagus

Question 27

what are the 3 steps to a diagnostic approach to regurgitation

Answer 27

1. distinguish from V+ or expectoration through history, physical exam, and watching P
2. rule out mechanical obstruction
3. rule out motility disorder