The Ear - B Davis Lec 1 Flashcards
function of auricle
sound collection and localization
sensory innervation to concha
auricular branch of CN X
sensory innervation to anterior aspects including tragus
auriculotemporal nerve (V3)
sensory innervation to variable, small distribution pattern
posterior auricular branch of CN VII
sensory innervation to posterior aspect of auricle aka lateral surfaces of lobule, helix, and anti-helix
Great Auricular Nerve (branch of cervical plexus)
sensory innervation to posterior aspect of auricle aka medial surfaces of lobule, helix, and anti-helix
Lesser Occipital Nerve (branch of cervical plexus)
innervation to external ear canal
auriculotemporal nerve (V3) and CN X
innervation to internal tympanic membrane
CN IX
what is the boundary between the external and middle ear
tympanic membrane
the tympanic membrane is anchored to the
manubrium of malleus
the middle hear houses:
3 tiny ossicles
chorda tympani (VII)
tensor tympani M
stapedius M
tympanic plexus (IX)
boundaries of middle ear
floor (inferior): tympanic portion of temporal bone
anterior: auditory/eustachian tube
lateral: tympanic membrane
posterior: mastoid air cells
medial: promontory of inner ear
roof (superior): tegmen tympani
the middle ear develops as an out-pocketing of the _________ , and retains this connection via the ______________-
pharynx , eustachian tube
Middle Ear: anterior communication
Eustachian tube to nasopharynx
Middle Ear: posterior communication
mastoid antrum
Middle Ear: medial communication –> oval window
footplate of stapes ; scala vestibuli
Middle Ear: medial communication –> round window
pressure release from scala tympani
the internal surface of tympani membrane is supplied by the ____________ from __________-
tympanic plexus ; CN IX
The tympanic nerve from CN IX is composed of
preganglionic parasympathetic and somatic sensory fibers
the tympanic nerve continues through the plexus to enter the cranial cavity as the
lesser petrosal nerve
the lesser petrosal nerve leaves through the
foramen ovale
the lesser petrosal nerve synapses at the
otic ganglion
lesser petrosal nerve postganglionic parasympathetic fibers hitchhike on the ____________ to innervate the ___________
auriculotemporal nerve (V3) ; parotid gland
what function do the preganglionic parasympathetic fibers have in the middle ear cavity
none
function of the ossicles
levers to magnify sound vibrations from the tympanic membrane to oval window of middle ear
the ossicles develop from which arches
1st and 2nd
stapes transmits sound waves from the ___________ to the __________ via the oval window
middle ear ; inner ear
the malleus does what when the membrane receives sound waves
vibrates
the incus transfers vibrations from the
malleus to stapes
the stapes receives vibrations from
incus
the stapes transfers vibrations via the footplate of the __________ of the ____________
oval window ; inner ear (scala vestibuli)
the facial nerve passes through the internal acoustic meatus with CN
VII
the geniculate ganglion houses what neuron bodies
1st order sensory neuron bodies
what nerve branches at the geniculate ganglion
greater petrosal nerve
the greater petrosal nerve carries what fibers and towards what ?
preganglionic parasympathetic fibers ; ptergopalatine ganglion
the facial nerve exits the base of the skull through the
stylomastoid foramen
what 2 nerves branch off the facial nerve in the facial canal
nerve to stapedius
chorda tympani
the chorda tympani passes between the
incus and malleus
the chorda tympani carries what fibers
taste fibers (anterior 2/3 of tongue)
preGPS fibers to submandibular ganglion
the chorda tympani merges with what nerve
the lingual nerve
the tensor tympani muscle does what
dampens excessive vibrations
the tensor tympani is innervated by the
CN V3
the stapedius muscle is innervate by
CN VII
the stapedius muscle does what
restricts movement
dampens vibration from loud noise
lesions that paralyze either the tensor tympani muscle or stapedius muscle can result in what
hyperacusis aka hypersensitivity to sound
the bony labyrinth is filled with what fluid
perilymph
the perilymph drains into the subarachnoid space via
the cochlear aqueduct
the oval window is occupied by
stapes footplate
the oval window receives vibrations into
scala vestibuli
the round window dissipates vibrations from
scala tympani
the membranous labyrinth contains what fluid
endolymph
endolymph drains into a sac in the subarachnoid space via the
vestibular aqueduct
the membranous labyrinth contains what 2 receptor organs for hearing and balance
cochlea and vestibular apparatus
the scala vestiboli and scala tympani communicate with one another at the
helicotrema
the vestibular apparatus is a region of membranous labyrinth for detection of
balance
position
movement
the inflated region near the cochlea in the vestibular apparatus houses the ______ and _______-
utricle and saccule
the utricle monitors what kind of balance
static balance - horizontal acceleration
the saccule monitors what kind of balance
static balance - vertical acceleration
the semicircular canals monitor what kind of balance
kinetic (angular movement of head on the APL planes aka rotational)
