Term
Understand the mechanism responsible for referred pain as it relates to the ear. |
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Definition
The external ear is innervated by cranial nerves V, VII, IX, and X.
Because of this innervation, the ear is a common location for referred pain. |
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Term
Be able to differentiate otitis externa from otitis media based on history and physical exam.
Patient presents with pain, redness, and swelling of the ear canal. Patient reports onset after hours of swimming (in warm water) and using a Q-tip to remove earwax.
On exam, tenderness with palpation exists over the tragus and movement of the pinna. Ear Discharge exists too.
What does the patient have?
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Definition
External otitis
History of...
Trauma: Q tips
Prolonged Moisture: Swimming
Occlusion: Ipod’s; Bony Exostosis
Diabetic patients may present with life threatening external otitis--malignant external otitis secondary to Pseudomonas aeruginosa leading to osteomyelitis |
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Term
| Understand the function of the tympanic membrane and know which landmarks are normally visible on otoscopy. |
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Definition
[image]
The tympanic membrane serves as a transducer converting sound waves into mechanical energy through the ossicles; amplifying sound up to 20 times. |
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Term
| Describe the Eustachian tube. |
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Definition
| The eustachian tube connects the nasopharynx to the middle ear space and is closed and opens briefly with swallowing. Many diseases of the middle ear are related to eustachian tube dysfunction. |
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Term
| Know what kind of movement stimulates the semicricular canals and what kind of movement stimulates the saccule and utricle. |
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Definition
semicircular canals: rotational motional
utricle and saccule: linear acceleration and gravitational force
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Term
| Differentiate between conductive and sensorineural hearing loss in terms of structures affected and results of the Weber and Rinne tests. Understand the mechanisms behind these two tests and how they allow the examiner to differentiate between the two types of hearing loss. |
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Definition
Conductive hearing loss - an interruption in the transmission of sound from the auditory canal to the oval window
etiology:
middle ear fluid (children),
typanosclerosis (adults) - calcification of the middle ear otoscleorsis (adults) - fixation of the stapes to oval window as a result of new bone formation within the labyrinth
perforated eardrum
cerumen
otitis externa or otitis media
Weber: Lateralizes to the affected ear
Rinne: BC > AC affected ear | AC > BC normal ear
Sensorineural hearing loss - a defect in the electric phase of hearing, i.e. either in the hair cell, 8th cranial nerve, and auditory cortex
etiology:
Cochlear hair cell damage (loud noise or medications)
8th nerve damage (acoustic neuroma)
Old age (presbycusis)
Weber: Lateralizes to the normal ear
Rinne: BC > AC bilaterally (but dimnished)
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Term
Understand the significance of recurrent serous otitis media in an adult in the absence of an antecedent upper respiratory infection.
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Definition
Even with a single episode of serous otitis media in an adult in the absence of an upper respiratory tract infection should prompt a careful eval for the presence of
nasopharyngeal carcinoma |
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Term
| Describe the anatomy of the medial and lateral walls of the nasal cavity. Which structures open up into the inferior meatus, the middle meatus, and the superior meatus? |
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Definition
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Term
Patient has a 4 year history of scube in open waters. What ear finding do you expect to see?
Patient presents with hearing loss |
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Definition
Exostoses - bony growths
these may interfere with the normal clearance of cerumen and squamous skin-debris => conductive hearing loss from total ear canal occlusion => maceration of ear canal skin => increase likelihood infection
Prevention: Use isopropyl alcohol drops in ear, mixed with some diluted acetic acid or vinegar |
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