Dz of Pharynx and Esophagus Flashcards
Which 5 cranial nerves are involved with swallowing?
- trigeminal - motor and sensory
- facial
- glossopharyngeal
- vagus
- hypoglossal - motor
How is the skeletal muscle component of the esophagus different between dogs and cats?
Dogs: striated muscle the entire length of the esophagus
Cats: striated muscle in the first 1/3 of the esophagus
What are the 4 phases of swallowing?
- preparatory oral
- oral
- pharyngeal
- esophageal
Describe the oral preparatory phase.
- voluntary
- mastication & lubrication of food
- abnormalities noted if there is dental disease, xerostomia, issues of the lips (CN V, VII), tongue (CN XII), cheeks (CN V and VII)
Describe the oral phase.
Food pushed caudally by the tongue into the pharynx
Describe the pharyngeal phase.
starts when the food reaches the tonsils
- elevation of the soft palate to prevent food from entering the nasopharynx
- closure of the entrance into the larynx: elevation and forward movement of the larynx and hyoid, retroflexion of the epiglottis and closure of the vocal folds
- synchronized contraction of the middle and inferior constrictor muscles of the pharynx together with relaxation of the cricopharyngeal muscles –> makes up the upper esophageal sphincter
Essentially, all oropharyngeal dysphagia fall into which two broad categories?
- failure for food to move down (abnormal bolus transfer)
- oropharyngeal pump failure (pharyngeal weakness)
- oropharyngeal and pharyngo-UES asynchrony (neuropathies)
- pharyngeal outflow obstruction (FB, tumour, cricopharyngeal achalasia) - abnormal airway protection
Describe the esophageal phase.
Involuntary
- once food bolus passes through upper esophageal sphincter into the esophagus
- peristalsis controls the speed of transfer
- primary peristalsis = induced by swallowing
- esophageal luminal distention - secondary peristalsis
- need the lower esophageal sphincter to be relaxed in advance in order for food to go into the stomach
What are the hallmark signs of esophageal phase dysphagia?
- regurgitation
- painful swallowing (odynophagia)
- repeated swallow attempt
- hypersalivation
What are some signs of oropharyngeal dysphagia?
- swallowing, gagging, retching associated with meals
- nasal regurgitation
- swallow related coughing
- food falling out while swallowing
- recurrent pneumonia
Which breeds are at risk for oropharyngeal dysphagia?
- Golden: pharyngeal weakness
- Cocker and Springer Spaniels: cricopharyngeal
- Bouvier and Cavalier: muscular dystrophy
- Boxers and Newfies: inflammatory myositis
Which breeds are more at risk for masticatory muscle distrophy?
Large breeds
What’s the gold standard for diagnosing acquired myasthenia gravis?
demonstration of antibody against acetylcholine receptor via RIA
What are some clinical signs of pharyngitits?
- Dysphonia
- Gagging
- coughing
- dysphagia
- hyporexia
- hypersalivation
- tonsilitis
How can one differentiate between pharyngeal weakness and cricopharyngeal dysphagia?
fluoroscopy
