Chapter 15: The Ear Flashcards
equilibrium and hearing receptors are located in ___
internal ear
hearing information is integrated and organized ___ and sent to __
in inner ear; CNS
hair cells are ___ in the inner ear
sensory receptors
structure of hair cells
free surfaces covered with specialized nonmotile processes
what are the 2 types of processes on hair cells?
- stereocilia
2. kinocilium
stereocilia
resemble long microvili
kinocilium
single large cilium
hair cells are what type of receptors?
mechanoreceptors
external force pushing on hair cells distorts plasma membrane and alters ___
neurotransmitter release
distortion of hair cells is monitored by ___
dendrites of sensory neurons
the distortion of hair cells provides information about ___ and __ of the stimulus
direction / strength
function of outer ear
collects / directs sound waves towards middle ear
what is the auricle?
elastic cartilage
what is the external acoustic meatus?
passageway in temporal bone
ceruminous glands secrete ___
waxy cerumen
function of waxy cerumen
keeps foreign objects out and slows growth of microorganisms
function of hairs in ears
trap debris
the middle ear is also called the ___
tympanic cavity
what is the middle ear?
air-filled chamber from tympanic membrane to auditory ossicles
the middle ear connects to pharynx by __
auditory tube
what is he tympanic membrane?
thin sheet that separates external and middle ear
what connects the tympanic membrane and inner air?
auditory ossicles
the inner ear contains __
sensory organs for hearing and equilibrium
the inner ear receives ___ from middle ear
sound waves
the auditory tube is also called the ___ tube
eustachian tube
the auditory tube connects the middle ear to the ___
nasopharynx
the auditory tube allows ____ equalization across the tympanic membrane
pressure
name of ear infection
otitis media
what are the 3 auditory ossicles?
- malleus
- inus
- stapes
the malleus attaches to __
tympanic membrane
the incus attaches __ to __
malleus to stapes
the stapes is attached to the ___
oval window
sound waves vibrate ___ (converting sound into mechanical movement)
tympanic membrane
auditory ossicles focus sound on the ___ and amplifies it
oval window
what is the bony labyrinth?
shell of dense bone surrounding / protecting membranous labyrinth
the bony labyrinth is filled with ___
perilymph
what is the perilymph?
fluid similar to CSF between the bony and membranous labyrinth
what are the 3 parts of the bony labyrinth?
- semicircular canals
- vestibule
- cochlea
what is the membranous labyrinth?
collection of fluid-filled tubes / chambers
the membranous labyrinth houses ___ for hearing and equilibrium
receptors
the membranous labyrinth contains a fluid called ___
endolymph
semicircular ducts house receptors that are stimulated by __
rotation of the head
what two structures are found within the vestibule?
utricle and saccule
the utricle and the saccule provide sensations of ___ and ___
gravity and linear acceleration
the cochlear duct is sandwiched between
perilymph-filled chambers
cochlear receptors are stimulated by ___
sound
what are the 3 semicircular ducts?
- anterior
- posterior
- lateral
the semicircular ducts are continuous with ___
utricle
the semicircular ducts are filled with
endolymph
what is the ampulla?
enlarged part of the semicircular duct that houses receptors
what is the ampullary cupula?
gelatinous structure that goes through the ampulla with kinocilia and sterocilia
movement in one direction causes ___; opposite direction causes ___
stimulation; inhibition
ampullary cupula rebounds to normal position when ___
endolymph stops moving
horizontal rotation stimulates ___ receptors
lateral duct
vertical movement stimulates ___ receptors
anterior duct
tilting head stimulates ___ receptors
posterior duct
the utricle and saccule provide ___ sensations, whether body is stationary or moving
equilibrium
utricle and saccule contain hair cells clustered in ___
maculae
the macula of the utricle senses __ movement
horizontal
the macula of the saccule senses __ movement
verticle
head in upright position, otholiths are __
on top of otolithic membrane of utricle
head in tilted position/linear movement, gravity pulls on otoliths and shifts them __
to the side
movement distorts hair cells and stimulates ___ receptors
macular
hair cells in the spiral organ lack ___
kinocilia
structure of hair cells in the spiral organ
stereocilia with overlying tectorial membrane
the bulk of hair cells in the spiral organ are embedded in __
basilar membran e
sound waves create ___ in the perilymph
pressure waves
pressure waves cause ___ to vibrate up and down
basilar membrane
vibrations of basilar membrane press sterocilia into ___, distorting them
tympanic membrane
distortion of stereocilia in the spiral organ triggers __
nerve impulse
sensory neurons relay signal through ___ to cochlear branch of vestibularcochlear nerve
spinal ganglion
sound
waves of pressure
wavelength of sound
distance between adjacent wave crests or troughs
if frequency increases, wavelengths ___
decreases
pitch
perception of frequency
high frequency = ___ pitch
high
intensity is ___
loudness; amount of energy in waves
amplitude of soundwave reflects amount of ___
energy (intensity)
intensity is measured in ___
decibels (dB)
___ of basilar membrane varies along its length
flexibility
location of vibration is interpreted as __
pitch
number of stimulated hair cells interpreted as __
volume
