Ear & Auditory Tube Flashcards
Lateral 1/3 is?
Medial 2/3 is?
- cartilagenous
2. bony
external accoustic meatus contains what?
hairy skin and Cerumen glands: prevent maceration with water
What 2 nerves innervate the ear?
Vagus
V3 auriculotemporal nerve
V3 auriculotemporal nerve innervates what in the ear?
anteriosuperior
external surface of tympanic membrane
Vagus innervates what in the ear?
posterioinferior inner ear
what’s the implication of V3 auriculotemporal nerve?
since part of trigeminal nerve, can have reerred pain from other areas like tooth to ear etc.
what’s the imprint on the tympanic membrane lateral surface?
handle of malleus
what shape is the tympanic membrane ?
concave externally
convex internally
why is the cone of light in the tympanic membrane important where should it be?
Antero-Inferior
shows the concavity, clinical sign
2 areas of middle ear are?
- epitympanic recess (to mastoid air cells)
2. tympanic cavity proper
what’s bad about infections in the middle ear?
can get into epitympanic recess, hard to drain, get into mastoid air cells. cause problems
differences in infant and adult Eustachian tube?
infant more horizontal = less drainage = more otitis media
cleft palate more likely to cause?
more eustuchian tube problems/otitis media
which ossicles is attached to tympanic membrane?
handle of malleus
which ossicle is attached to oval window?
stapes
what two muscles dampen sound? innervations?
Stapedius: Seventh nerve (Facial)
Tensor Tympani: Trigeminal (trigeminal)
what conditions don’t allow dampening of sound, why?
acoustic neuromas that compress trigeminal/facial nerve palsies
Chorda tympani part of?
facial nerve
what is the promontory?
basal turn of the cochlea
facial nerve emerges where?
stylomastoid foramen
what vital vessel is close to middle ear?
internal carotid
what are the two labyrinths in the inner ear what fluid do they contain?
Bony Labyrinth: perilymph
Membranous labyrinth: endolymph
bony labyrinth is located?
petrous part of temporal bone
what contains the sensory receptros for hearing?
cochlear duct
what senses static equilibrium?
utricle
saccule
what senses dynamic equilibrium?
ampulla of the semicircular ducts
utricle
saccule senses what?
static equilibrium
ampulla of the semicircular ducts senses?
dynamic equilibrium
where in the cochlea are high and low frequencies detected?
High Freq: base
Low Freq: apex of cochlea
Saccule is vertical or horizontal?
Vertical
Utricle more vertical or horizontal?
Horizontal
