Exercise 11 Flashcards
frequency and intensity are detected by
the sensory receptors in the ear and interpreted in the auditory cortex of the brain
Cochlear branch of vestibulocochlear nerve (VIII)
responsible for conducting the impulse from the cochlea to the auditory cortex
frequency
the number of cycles or oscillations per second; the frequency. of sound determines the pitch of. a sound; higher frequency. = higher pitch; deflects the basil membrane closer to the oval. window and stimulate the hair cells in that area. of the cochlea
intensity
loudness of a sound is determined by the amount of deformation of the hair cells; the higher the decibels, the louder the sound and the greater the deformation. of the hair cells resulting in the generation of more action potentials
air conduction
transport sound waves through the external auditory canal, tympanic membrane, ossicles, and. oval window to the cochlea; disruptions in this pathway result in conductive hearing loss
bone conduction
transports sound waves through the bones of the skull to. the cochlea
sensorineural hearing loss
a result of a disruption of the cochlea, the hair cells specifically, or cranial nerve VIII, or presbycusis or inner ear infections
presbycusis
as hair cells are exposed to prolonged or loud noises, they may be damaged and no longer able to respond to stimulation; a decrease in the ability to detect sounds in the upper frequencies
Central hearing loss
due to defects in the tracts of the CNS associated w the auditory pathway or defects in the auditory cortex; CNS infections, tumors, and oxygen availability
equilibrium
involves the vestibular system and is responsible for the detection of body position in space, position relative to gravity, and also acceleration and deceleration
there are multiple. sets of sensory receptors involved in equilibrium, one in the ampulla of. each of the semicircular canals and one in the macula of each of the trickles and saccules
the vestibular branch of. the vestibulocochlear nerve
responsible for conducting the impulse from the vestibular apparatus to the brain, where the info is integrated w additional info from the eyes, proprioceptors, and pressure receptors; also responsible for collecting sensory info for the vestibule-ocular reflex
vestibule-ocular reflex
allows the eyes to fix on a references point in your visual field as your body moves
vertigo
when the sensory receptors of the vestibular apparatus are stimulated by excess rather than by movement, this is what the person may experience
Meniere’s disease
common pathologic causes of vertigo; will experience tinnitus due to overproduction of endolymph throughout the inner ear
audiometer
used to test a person’s ability to. detect specific frequencies at specific decibel levels; used to detect hearing loss by identifying the minimum decibel level at which a particular frequency can be heard; reference threshold set at 0 dB; the person’s threshold intensity for each frequency tested is graphed on an audiogram
Weber’s test
uses the localization of hearing to detect either conductive or sensorineural hearing loss; sound should lateralize to the blocked ear; blocking the ear simulates a hearing loss due to a reduction in air conduction. bc this ear does not carry as much sound from air conduction, the cochlea is more sensitive to the sounds carried by bone conduction. Therefore this would indicate a conductive loss
Rinne’s test
compares air conduction w bone conduction to detect the location of conductive hearing loss; the sound should be heard via air conduction longer than via bone conduction. if air conduction does not last longer than bone conduction, then the person has conductive hearing loss
nystagmus
the involuntary but rhythmic movement of the eyes
past pointing
the inability of a person to accurately touch the outstretched fingertips of another person
rotational nystagmus
person moves to the right, semicircular canals move with the person, but the endolymph in the canals doesn’t;t move as quickly so the endolymph appears to move counterclockwise. and pushes on the ampulla and bends the hair cells. this will result in depolarization of the hair cells on the right side of the head. and hyper polarization of the hair cells on the left side of the head. this continues until the speed of endolymph movement catches. up and matches the speed of rotation
postrotational nystagmus
when the subject stops rotating, the semicircular canals stop moving but the endolymph in the canals continues to move so it pushes on the ampulla. in the opposite direction. this. bends the hair cells in the opposite direction resulting in hyper polarization of the hair cells on the right side of the head and depolarization of the hair cells on the left side of the head
Barany’s test
test for proper functioning of the vestibular apparatus (person spinning in a chair)
