PSL300 term test 2

pinna, ear canal; tympanic membrane/eardrum

The external ear contains the ___________ and the ___________ and ends at the ___________.

air-filled, pressure, ossicles

The middle ear is a(n) ___________ chamber that equalizes ___________ and contains the ___________.

malleus, incus, stapes, middle, inner, smaller window

The ossicles are the three bones (__________, __________, and __________) in the __________ ear that carry vibrations to the __________ ear; form the lever system that concentrates vibration onto a __________ (efficient transfer).

oval window

membrane-covered opening that separates the middle ear from the inner ear

cochlea, vestibular apparatus

The inner ear contains the sensory organs the ___________ and the ___________.

sound

a wave of pressure traveling through (usually) air, water, or solid objects

peaks, compressed together

Sounds have high and low pressure regions. Regions with high pressure are referred to as ___________ and have molecules that are (compressed together/further apart).

troughs, further apart

Sounds have high and low pressure regions. Regions with low pressure are referred to as ___________ and have molecules that are (compressed together/further apart).

frequency

the number of wave peaks that pass each second; represented in Hz; perceived as pitch

16 to 20,000; 1k-3k

Humans perceive from _____ to _____ Hz, but our highest acuity is from _____ to _____ Hz.

amplitude

the difference in pressure between peak and trough (larger → louder; smaller → quieter)

vestibular

the upper duct of the cochlear where perilymph fluid waves are launched

cochlear

the central duct of the cochlear where endolymph fluids are sealed off; contains hair cells

organ of Corti

hair cells are found here

hair cells

specialized epithelial mechanical receptors; there are about 20,000 in each cochlea

tympanic duct

the lower duct of the cochlear where pressure waves dissipate due to a flexible membrane

round window

in the tympanic duct, bulges outward to allow fluid movement and pressure relief

helicotrema

communication between tympanic and vestibuar ducts occur here, permitting a small helicotrema

VIII

The auditory/cochlear nerve is Cranial Nerve ___.

II

The optic nerve is Cranial Nerve ___.

III

The oculomotor nerve is Cranial Nerve ___.

III-X; XII

The brainstem is comprised of the Cranial Nerves __ through __ and ___.

stereocilia

stiff, hair-like projections on the surface of hair cells; mechanoreceptors that convert sound energy into electrical signals for hearing and balance

de, more, more

Stereocilia bends towards longest cilium → hair cell (de-/hyper-)polarizes, releasing (less/more) neurotransmitters onto a nearby primary sensory neuron and generating (fewer/more) APs.

hyper, less, fewer

Stereocilia bends towards shortest cilium → hair cell (de-/hyper-)polarizes, releasing (less/more) neurotransmitters onto a nearby primary sensory neuron and generating (fewer/more) APs.

narrow/stiff; higher

The basilar membrane near the oval window (the base of the cochlea) is more (narrow/wide)/(flexible/stiff). (Higher/lower) frequency sounds produce greatest vibration here.

wide/flexible; lower

The basilar membrane near the helicotrema (the apex of the cochlea) is more (narrow/wide)/(flexible/stiff). (Higher/lower) frequency sounds produce greatest vibration here.

loudness, timing, bilateral processing

Comparing signals (______________, ______________) from each ear to determine where sounds are coming from is also known as ______________.

A1/auditory cortex/temporal lobe

Conscious processing of what we are hearing occurs here

same

Cochlear nuclei receive input from the (opposite/same) ear.

eardrum → malleus/incus/stapes → oval window → basilar membrane → organ of corti → auditory nerve → cochlear nuclei (medulla) → midbrain → medial geniculate nucleus → A1

Please describe the auditory processing pathway.

conductive

In this type of hearing loss, sound can’t be transmitted effectively through the external or middle ear (earwax, torn eardrum, ossicle damage, etc.)

conductive, normal air conduction, teeth, skull, cochlea

Beethoven had _________ hearing loss. He bit into a rod connected to his sound board so that vibrations could bypass the __________ pathway, traveling through the __________, __________, and the __________

sensorineural

In this type of hearing loss, there is damage to the inner ear (e.g., damage to cochlear hair cells)

sensorineural, presbycusis

The most common type of hearing loss is _________. Most of hearing loss in the elderly, i.e., _________, is this.

central

In this type of hearing loss, there is damage to the auditory pathway/A1 (e.g., know that someone is speaking, but it sounds like gibberish)

Rinne test; conductive

_________: A hearing loss test where one strikes a tuning fork and places the handle against the mastoid bone. If the sound is louder via the bone, we conclude that there is _________ hearing loss.

Weber

_________: A hearing loss test where one strikes a tuning fork on the forehead. If the sound is louder via the bone, we conclude that there is _________ hearing loss.