what glands are present in the external acoustic meatus?
ceruminous glands
what composes the outer ear?
auricle
external acoustic meatus
tympanic membrane
what does the tympanic membrane do?
transfers sound energy to the middle ear
what is the roof of the middle ear cavity?
epitympanic access
what allows for communication with mastoid air cells housed in the mastoid process?
mastoid antrum in middle ear
what is the importance of the eustachian tube?
equalizes pressure in middle ear cavity with external air pressure allowing the eardrum to vibrate freely
where are the auditory ossicles located?
what are they?
middle ear
malleus
incus
stapes
what transmits the vibratory motion of the tympanic membrane to the oval window?
stapes
what two muscles minimize damage to hearing receptors?
tensor tympani
stapedius
what are the two divisions of the internal ear?
bony labyrinth
membranous labyrinth
what fills the bony labyrinth?
perilymph
what fills the membranous labyrinth?
endolymph
state two functions of perilymph and endolymph
conduct sound vibrations
respond to mechanical forces occurring during changes in body position and acceleration
what are the three regions of the bony labyrinth?
vestibule
semicircular canals
cochlea
what are the two membranous labyrinth sacs suspended in the vestibular perilymph?
saccule
utricle
what is housed within the saccule and utricle?
maculae
what structure responds to the pull of gravity and reports to changes in head position?
maculae
what are the three semicircular canals?
lateral semicircular canal
anterior semicircular canal
posterior semicircular canal
what is found within each semicircular duct of the semicircular canals?
crista ampullaris
what is the function of the crista ampullaris?
responds to rotational movements of the head
what is the membranous structure within the cochlea?
cochlear duct
what is housed within the scala media of the cochlear duct?
spiral organ
what are the cells of the spiral organ?
cochlear hair cells
Afferent fibers of the __________ coil around the bases of the hair cells and runs from the __________ through the modiolus of the brain
cochlear nerve
spiral organ
what three chambers composes the cavity of the cochlea?
scala vestibuli
scala media
scala tympani
what liquid is found in the scala vestibuli?
perilymph
what liquid is found within the scala media?
endolymph
what liquid is found within the scala tympani?
perilymph
scala tympani and scala vestibuli are continuous with each other at the cochlear apex region called the ______________
helicotrema
what is the roof of the cochlear duct?
what does it contain?
what does this structure secrete?
vestibular membrane
stria vascularis
endolymph
what is the floor of the scala media of the cochlear duct?
what is its function
basilar membrane
supports the spiral organ in sound reception
what are the hair cells of the macula?
stereocilia
kinocilium
where are the hairs of the macula embedded in?
what does this jelly-like mass structure contain?
what are their function?
otolith membrane
otoliths
increase the membrane's weight and its resistance to changes in motion or inertia
in the utricle the macula is ________
this allows the utricular macula to respond best to acceleration in the _____________________________
horizontal
horizontal plane and tilting the head
in the saccule the macula is nearly _______
this allows the saccular maculae to respond best to _______________________________________
vertical
vertical movements
when hairs bend toward kinocilium the:
hair cells ________
increases the _____________
depolarize
amount of neurotransmitters released
when hairs bend away kinocilium
receptors ___________
release less _____________
hyperpolarize
neurotransmitters
instead of an otolith membrane, the crista ampullares has a pointed cap structure called the _______________
ampullary cupula
how are receptors of the crista ampullares activated?
flowing endolymph bending the ampullary cupula and exciting the hair cells