Exercise 11

Question 1

frequency and intensity are detected by

Answer 1

the sensory receptors in the ear and interpreted in the auditory cortex of the brain

Question 2

Cochlear branch of vestibulocochlear nerve (VIII)

Answer 2

responsible for conducting the impulse from the cochlea to the auditory cortex

Question 3

frequency

Answer 3

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

Question 4

intensity

Answer 4

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

Question 5

air conduction

Answer 5

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

Question 6

bone conduction

Answer 6

transports sound waves through the bones of the skull to. the cochlea

Question 7

sensorineural hearing loss

Answer 7

a result of a disruption of the cochlea, the hair cells specifically, or cranial nerve VIII, or presbycusis or inner ear infections

Question 8

presbycusis

Answer 8

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

Question 9

Central hearing loss

Answer 9

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

Question 10

equilibrium

Answer 10

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

Question 11

the vestibular branch of. the vestibulocochlear nerve

Answer 11

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

Question 12

vestibule-ocular reflex

Answer 12

allows the eyes to fix on a references point in your visual field as your body moves

Question 13

vertigo

Answer 13

when the sensory receptors of the vestibular apparatus are stimulated by excess rather than by movement, this is what the person may experience

Question 14

Meniere’s disease

Answer 14

common pathologic causes of vertigo; will experience tinnitus due to overproduction of endolymph throughout the inner ear

Question 15

audiometer

Answer 15

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

Question 16

Weber’s test

Answer 16

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

Question 17

Rinne’s test

Answer 17

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

Question 18

nystagmus

Answer 18

the involuntary but rhythmic movement of the eyes

Question 19

past pointing

Answer 19

the inability of a person to accurately touch the outstretched fingertips of another person

Question 20

rotational nystagmus

Answer 20

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

Question 21

postrotational nystagmus

Answer 21

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

Question 22

Barany’s test

Answer 22

test for proper functioning of the vestibular apparatus (person spinning in a chair)