ear Flashcards
the three subdivisions of the ear are
external ear
middle ear (tympanic cavity)
inner ear
the external ear consists of the
auricle and the external acoustic meautus
auricle is a
elastic fibrocartilollage covered by skin
function of auricle
to collect air vibrations
externakl acoustic meatus extends from the
auricle to thetympanic membrane
external acoustic meatus framework is
lateral third is cartilaginous and medial two third is bony
does teh auricle have extrinsic or intrinsic muscles or both
both
motor nerv supply of the ear
facial nerve for all muscles of teh auricle
cutaneous supply
lesser occipital nerve
auriculotemporal nerve
greater auricular nerve
auricular branch of vagus
how does the tymapnic membrane lie
obliquely between the middle ear and teh external ear
outer surface of the tympanic membrane
it contaisn a depressed surface called teh umbo
inner surface of teh tymanic membrane
it give attachment to the handle of malleus (center)
the middle ear description
air filled cavity of the petrous portion of temporal bone
lies between the external ear laterally and teh inner ear medially
contents of teh middle ear
air, three bony ossciles, two muscles, vessels, nerves (chorda tympani and temporal plexus )
roof of the tympanic cavity
tegmen tympani: thin plate of bone
floor of the tympanic cavity
internal jugular vein
lateraly eall of thhe tympanic cvaity
tympanic membrane
posterior wall of tympanic cavity
vertcial part of facial nerve
medial wall of tympamic cavity
promontory , oval and round window, horizantal part of facial nerve
anterior wall of tymapnic cavity
phrayngeotymapnic tube 9 audiotroy tube) internal carotid artery and tensor tympani muscle
function of phrayngeotympanic tube
it serves to equalize the air pressure in the tympanic cavity ad teh nasophraynx
phrayngeo tympanic tube framework
posteriro inner third is bony and anterior two third is cartiligenous
the audiotory ossicles
malleus ( hammer)
stapes ( stirrup)
incus ( anvil)
muscles of the middle ear
tenspor tympani and stapedius
stapedius nerve supply
facial nerve
tensor tympani nerve supply
mandibular division of trigimenal nerve
action of stapedius
dampens excessive noise vibratiosn
action of tensor tympani
tenses tehtympanic membrane and pulls tehhandle of malleus medially
inability to dampen loud noises is called
hyperacusis
the inner ear consists of
auditory and vestibular structures filled with fluid
function of the inner ear
hearing sound audiotory and maintaining the balance of the body vestibular
inner ear location
situated within the petroud part of the temporal bione between the middle ear laterally and the internal acoustic meatus
inner ear divisons
bony and membranous labyrinth
what labyrinh is suspeneded within the bony labyrunth
membranous
bony labyrinth consists of
vestibule, cochlea, and semicircular canals
cochlea is responsile for
hearing
vestibule is responsible for
balance while stationary
on its lateral wall lies
oval window enclosed by stapes and round window sealed by secondary tympanic membrane
semicircular canals responsible for
balance while in motion
threee canals
anteriro posterior and lateral
membranous labyrinth contaisn
perilymph
membranous labyrinth conisists of
the vesitbular apperatures and the cochlear duct
the vestibular apperatures afre
utricle, saccule, semi circular ducts
the cochlear duct is
situated within the cochlea and is the organ responsible for hearing
scala tympani and scala vestibuli
