Ear Anatomy Flashcards
is the lateral 1/3 of the external acoustic meatus cartilage or bone?
cartilage
is the medial 2/3 of the external acoustic meatus cartilage or bone?
bone that connects with tympanic membrane
what is the roof of the middle ear formed by?
tegmen tympani
what CN traverses in the middle ear?
facial nerve
name the three bones of the middle ear
malleus incus and stapes
what bone is against the tympanic membrane?
malleus
what bone covers the oval window?
stapes
what does the oval window lead to?
the inner ear
what is just inferior to the round window?
oval window
what are the two muscles of middle ear?
tensor tympani
stapedius
what is the role of the muscles of the middle ear?
they protect the ear from loud sounds
what nerve innervated the tensor tympani?
V3
what nerve innervates the stapedius?
facial nerve
what is role of tensor tympani?
tenses the eardrum
what is role of the stapedius?
dampens vibrations going into the oval window
what is the central depression in the tympanic membrane called?
umbo
what bone can you see on tympanic mem?
handle of the malleus
what bone does the tensor tympani insert on?
malleus
what is the bulge of the middle ear called?
promontory
where in the middle ear is the promontory?
medial most aspect
what are the components of the vestibular apparatus in the inner ear?
semicircular canals and utricle and saccule
what are the utricle and saccule responsible for in the inner ear?
vestibular sensation of linear accelerations
what is the semicircular canal in charge of in vestibular system?
angular acceleration changes
what is the inner ear area called?
bony labyrinth
what is the bony labyrinth filled with?
perilymph
what is suspened within the bony labyrinth?
membranous labyrinth
what is the membranous labyrinth filled with?
endolymph
what four things are in the membranous labyrinth?
cochlear duct
utricle and saccule
semicircular ducts
what are the specialized sensory epithelium of the utricle and saccule called?
maculae
what is the ampulla?
small swelling at base of semicircular ducts
what does the ampulla have in it?
crista
what are crista?
specialized sensory cells of the semicircular duct that responds to rotational movement
how many turns does the cochlea make?
2.5
what are the three chambers of the cochlea
scala vestibula
scala tympani
scala media (cochlear duct)
what chambers of the cochlea contain perilymph?
scala vestibuli and scala tympani
what chamber of the cochlea contains perilymph?
scala media (cochlear duct)
what are the two membranes that separate chambers in the cochlea?
vestibular and basilar membranes
where is the specialized epithelial cells in the cochlea?
organ of corti
what is the membrane of the organ of corti?
tectorial membrane
vibrations from the oval window enter into what chamber of the cochlea?
scala tympani
the vibrations travel in the scala tympani until where?
the helicotrema
what happens to vibrations at the helicotrema?
they get transmitted into the scala vesitbuli
what does the pressure wave moving through the scala tympani/vestibuli cause in the organ of corti?
pressure wave there too that stimulates nerve ending on end of organ of corti
what nerve provides sensory innervation to the tympanic cavity?
glossopharyngeal
what nerve plexus can be seen in the tympanic cavity? what is it called?
tympanic plexus of the glossopharyngeal nerve
what is sensation nerve for area around entrance to and the external acoustic meatus?
vagus nerve
what is sensation on anterior portion of outer ear?
trigeminal nerve V3
what is sensation on posterior portion of outer ear?
facial nerve
