Ears Flashcards
What are the three compartments of the ear?
-External ear
-Middle ear
-Inner ear
What comprises the external ear?
The auricle and ear canal
What is the auricle?
Consists of cartilage covered by the skin
What is the outer curve of the ear called?
Helix
What is parallel and anterior to the helix?
The antihelix
What is the Tragus?
A modular protrusion that points backward over the entrance to the canal
What is the approximate length of the ear canal
24mm long
What is at the end of the ear canal?
Tympanic membrane
*Ear drum
*Marks the medial limit of the external ear
What is the function of the external ear?
Capture sound waves for transmission into the middle and inner ear
What is the middle ear filled with?
Air
What are ossicles?
Tiny bones that function to transform sound vibrations from the external ear into mechanical waves
What are the three ossicles in the middle ear?
Malleus
Incus
Stapes
Which ossicles are visible through the TM
Malleus and the incus
What does the middle ear connect to?
Connects to the nasopharynx via the proximal end of the Eustachian tube
What is the function of the Eustachian tube?
It ventilates the middle ear space and allows for pressure regulation between the middle ear and surrounding environment
*Will also drain mucus from middle ear into the nasopharynax
What is the inner ear composed fo?
Cochlea
Semicircular canals
Otolith organs
*In the vestibule
Distal end of vestibulocochlear nerve VIII (CN VIII)
What is the function of the cochlea?
Dedicated to hearing
What is the function of the semicircular canals and the otolith organs?
Balance/Equilibrium
What do the semicircular canals, otolith organs, and the cochlea form?
The labyrinth
What is the first part of the hearing process?
Conductive phase
*from external ear through the middle ear
What is the second part of the hearing process?
Sensorineural phase (inner ear)
*cochlea to the nerve
*CN VIII vestibulocochlear
If you have conductive hearing loss what structures are affected?
Disorders of the external and middle ear
If you have sensorineural hearing loss what structures are affected?
Inner ear
What is air conduction?
The normal first phase in the hearing pathway
*sound waves travel through the air transmitted from the external and middle ear to the cochlea
What is bone conduction (Alternative pathway)
Bypasses the external and middle ear
*can be used to determine hearing loss
In normal situation what should last longer AC or BC?
AC>BC
What is otitis externa?
Inflammation of the external ear canal
What is otitis media?
Infection of the middle ear
What is tinnitus and what should be suspected when a patient has tinnitus?
Ringing in the ears
*vertigo or Meniere disease
What are symptoms of vertigo?
Feeling like the room is spinning
What is the tug test?
Use if ear pain, discharge, or inflammation is present
*Move the auricle up and down press the tragus
How should you move the patients ear when examining the TM?
gently upward, backward, and slightly away from the head
What are exostosis?
Non-tender modular swelling covered by normal skin deep in the ear canal
*caused by repeated exposures to cold water
*benign
*Surfers Ear
What is the whisper test used for?
To test auditory acuity
*CN VIII
When do you use the Weber and Rinne fork test?
For patients who failed the whispered voice test
*Used to determine if the hearing loss is conductive or sensorineural
*if hearing loss is suspected
What tuning fork do you use for Weber and rinne tests?
512Hz
What does the Weber test test for?
Lateralization
*Place in the midline
For conductive hearing loss where does the sound lateralize to? (Weber test)
The affected ear
For sensorineural hearing loss where does the sound lateralize to? (Weber test)
The good ear
*CN VIII impairment in the other ear (affected side)
What does the Rinne test test for?
Compare AC to BC
If there is conductive hearing loss which is longer AC or BC?
BC=AC or BC>AC
If there is sensorineural hearing loss what is longer AC or BC?
AC>BC
What is a tophi?
A deposit of uric acid crystal characteristic of chronic tophaceous gout
*appear in the helix or antihelix
*Develops after chronic sustained high blood levels of Uric acid
What is a chondrodematitis helicis?
Chronic inflammatory lesion starts as a painful, tender papule on the helix or antihelix
What is tympanosclerosis?
Chalky white patches
Does not impair hearing
May follow an episode of otitis media
*Benign
What encases the outer 1/3 of the ear canal?
Cartilage
Hair
Cerumen
What encases the inner 2/3 of the canal?
Bones
Hairless
What can causes pain during the ear examination?
Pressing on the inner 2/3 of the ear canal
What is bulbous myringitis?
Common sequela presenting with painful hemorrhagic vesicles on the TM
What causes a serous effusion
URI
OR sudden changes in the atmospheric pressure
*collection of non-infected fluid in the middle ear
