unit 8: special senses, inner ear (labyrinth) Flashcards
two parts of labyrinth:
___ labyrinth is an enclosure for the ___ labyrinth, which is bathed by perilymph from w/i the former
bony
membranous
three parts of bony labyrinth
cochlea
vestibule
semicircular canals
the __ is snail shell shaped and contains the cochlear duct, while the ___ contains the utricle and saccule
cochlea
vestibule
part of bony labyrinth that has lateral, anterior and posterior parts, and contain the semicircular ducts
semicircular canals
there is ___ within the membranous labyrinth, which contains a ___ labyrinth and a ___ labyrinth
endolymph
cochlear
vestibular
utricle saccule semicircular ducts utricosaccular duct endolymphtic duct endolymphatic sac ductus reuniens --are all found in the \_\_\_ labyrinth of the membranous labyrinth
vestibular
the bony part of the cochlea consists of a tube that is coiled 2.5-2.75x around a cone shaped central bony structure called the ___
modiolus
apex of the cochlea, which is directed anterolaterally
cochlear cupula
bony ridge that connects the cochlea to the modiolus
lamina of the modiolus
three channels of the cochlea
chochlear duct
scala vestibuli
scala tympani
the __ __ ends at the apex of the cochlea, and the scala vestibuli and scala tympani communicate with e/o at the apex thru a channel called the ____
cochlear duct
helicotrema
- __ ___ is above the cochlear duct and is filled with perilymph.
- OVAL window forms its base so ___ are transmitted into it as the stapes
scala vestibuli
vibrations
- __ __ is below the cochlear duct, and it recieves vibrations from the scala vestibuli via the helicotrema
- ___ window forms the base
scala tympani
round
the cochlear duct is in the middle of the __ __, with the scala vestib above and scala tymp below
-filled with ___
bony labyrinth
endolymph
the cochlear duct is attached to the ___ of the modiolus and anchored to the outer wall of the cochlea by the __ __
lamina
spiral ligament
cochlear duct is separated from the scala VESTIB by the ___ membrane, and from the scala TYMP by the ___ membrane
vestibular
basilar (spiral)
the __ __ is lcoated on the floor of the cochlear duct, attached to the basilar/spiral membrane
spiral organ
hairlike projections from the basilar/spiral membrane project superiorward in the __ __, and are sensitive to ___ & amplitude of soundwaves entering the cochlea
spiral organ
frequency
hair cells of the spiral organ are covered by the __ __ and info will be conveyed from receptor cells to primary sensory neurons, which have cell bodies in the ___ ganglion
techtorial membrane
spiral
sound transmission (1):
- waves enter the EAM, causing __ __ to vibrate
- ___ of middle ear transmit vibrations & amplify 1.2 times (maleus, incus, stapes)
- the foot of stapes articulates with __ window, at the base of the scala vestib & amps the sound another 17 times
tympanic membrane
ossicles
oval
sound transmission (2):
- vibs from oval window transmit thru ___ of scala bestib and tymp, to reach the round window
- wave transmitted causes __ __ to vib, stims receptors in spiral organ
- info transmitted to __ nerve
perilymph
basilar membrane
cochlear
vestibular labyrinth consists of 2 sacs, __ & ___ and 3 semicircular ducts (ant, lat, post)
-endolymph in all
saccule
utricle
in the vestib labyrinth, the __ comm with the cochlear duct, while the larger ___ comm with all 3 semicirc ducts, as well as with the former via the utricosaccular duct
saccule
utricle
hairlike sensory organ projections w/i saccule and utricle bathed in endolymph
maculae
- organs floating on endolymph surrounding maculae
- movements of head cause them to deflect the maculae, eliciting impulses
otoliths
the ___ detects linear accel while the the ___ detects centrifugal and vertical accel
saccule
utricle
sense organs w/i the semicirc ducts that are located in the ampulla of each
crista
semicircular ducts are sensitive to accel in any direction, but are partic sens to ___ accel
rotational
impulses initiated by the sense organs w/i the vestib labyrinth are carried by neurons with CB in the ___ ganglion
- dendrites to it collected in superior & inferior branches
- axons from ganglion make up vestib nerve
vestibular
the SUPERIOR branch is larger, carries info from the __ & __ semicirc ducts, utricle, and some from the saccule (voit’s)
-12k fibers
anterior
lateral
the INFERIOR branch carries info from the __ semicirc duct and the ___
-8k fibers
posterior
saccule
two arteries supplying blood to the labyrinth
internal auditory (from basilar a.) stylomastoid (from post auricular a)
sympathetic nerve supply to the labyrinth is from the ___ and/or ___ ___ plexuses
cavernous
internal carotid
__ nerve is composed of axons from cells in spiral ganglion
cochlear
- in the labyrinth, info is relayed thru the cochlear nuclei to the __ __ and __ nuclei in the MO
- info then carried in the lateral lemniscus to the inferior colliculi and medial geniculate bodies
- relayed to temp lobe, Brodmann areas __ & __
superior olivary
trapezoid
41 & 42
- vestib nerve is made up of axons from the ___ ganglion
- these axons are carried to __ __ __ of the MO
- info processed in cerebellum
vestibular
vestibular nuclear complex
