Ear Flashcards
(29 cards)
Skeletal portions of the ear
- squamous (includes mastoid process & air cells)
- petrous (contains labyrinths of inner ear)
- tympanic (houses external auditory meatus)
external ear parts?
auricle and external auditory meatus
auriclre?
(pinna, concha) – skin-covered cartilage with extrinsic and intrinsic muscles (degenerate in humans).
ext auditory meatus
Funnel-like tube of cartilage and bone, formed from first branchial groove. Contains sebaceous and ceruminous glands and hair follicles.
function of the middle ear
Converts sound waves in air to vibrations of solid structures (membrane and bone); amplifies the sound and transmits it to the inner ear.
eardrum is attached to the
Manubrium of the malleus
what archs are the ossicles derived from
incus and malleus - 1st
stapes- 2nd
epitympanic recess
portion of the tympanic cavity that houses most of the incus
oval window
oval window (fenestra vestibuli) in which lies the footplate of the stapes;
function of the auditory tube
The auditory tube (formed from first branchial or pharyngeal pouch) equalizes air pressure on both sides of the eardrum.
promontory
The medial wall has a bulge (the promontory) formed by the cochlea; above this is the oval window
function of malleus and incus
decrease amplitude of soundwaves while multiplying their force
tensor tympani ?
tenses the eardrum and dampens strong vibrations
the sensory gangion of cn7 is the the geniculate ganglion what are the 2 branches
chordae tympani
nerve to stapedius
tympanic plexus relates to ?
sensory nerves to tympnic cavity from cranches of CN9
Inner ear function ?
converts vibrations of the ossicles to waves in liquids ?
bony labyrinth
bony labyrinth, a series of passages inside the petrous part of the temporal bone, filled with perilymph. These passages are the vestibule, the 3 semicircular canals, and two parts of the cochlea: the scala vestibuli and scala tympani.
membranous labyrinth
and adhering to their walls, are the similarly-shaped structures of the membranous labyrinth, containing endolymph. These include the saccule, utricle, 3 semicircular ducts (each with an ampulla), and the scala media (cochlear duct).
neuromast organs,
The inner ear contains 3 types of modified neuromast organs, one for hearing (called the organ of Corti, spiral organ, or organ of hearing) and two for equilibration (called respectively the crista ampullaris or ampullary crest, and the macula
capula of the neuromast organs
organ of corti–techtorial membrane
crista ampullaris- cupula
macula otolithic membrane
organ of corti
send impulses to the brain via CN8
scala and the membranes ?
The scala vestibuli and scala media are separated by the vestibular membrane. The scala media and scala tympani are separated by an osseous spiral lamina and by the basilar membrane
Organ of hearing can be found in the
scala media
Its hair cells of the scala media are embedded in a modified cupula, the ___ which is attached only to the spiral lamina.
tectorial membrane