Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Brain and Behavior > Lectures 20-22: Auditory System > Flashcards

Lectures 20-22: Auditory System Flashcards

You may prefer our related Brainscape-certified flashcards:
The Brain flashcards
1
Q

Audible range in Hz and dB. What frequency are we most sensitive?

A

20 - 20,000 Hz (1,000 - 3,000 we are most sensitive) and 1 - 120 dB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

External ear: parts and functions

A

Pinna (reflects low frequencies for vertical sound localization) and external auditory meatus (magnifies 3,000 Hz sound by passive resonance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Middle ear: parts

A

Ossicles (malleus, incus, stapes), muscles (tensor tympani, stapedius), eustachian tube

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where does the stapes foot plate insert?

A

Oval window

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Tensor tympani muscle innervation and function. What bone does it attach to?

A

Innervated by CNV, improves transmission of high frequencies; malleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Stapedius muscle innervation and function

A

Innervated by CNVII, stiffens chain of ossicles to dampen sound (stapedius reflex)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Cochlea: parts, fluid, and function. Describe why one of the fluids is special.

A

Bony cochlea (filled with perilymph) and membranous cochlea (filled with viscous endolymph [high K+, low Na+])

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Three cochlear compartments

A

Scala vestibuli (in), scala media (membranous), scala tympani (out)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How is sound transmitted?

A

Stapes oscillates, pressure wave transmitted through oval window –> scala vestibuli –> scala tympani (base to apex) –> round window

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where does hearing happen? Two membranes flanking scala media? Third membrane? Where are the hair cells?

A

Scala media; vestibular and basilar membrane; tectorial membrane; sit on basilar membrane and extend to tectorial membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Organ of Corti consists of…

A

Basilar membrane, inner and outer hair cells, tectorial membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Stria vascularis

A

Highly vascular structure that produces endolymph on lateral wall of Organ of Corti

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Inner hair cells

A

Single row, responsible for hearing, 95% of input to auditory nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Outer hair cells

A

Three rows, critical for audition: input from superior olive, sharpen sound frequency resolution, protect hair cells from loud noise, otoacoustic emissions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Hair cells “hairs”

A

Sterocilia (arranged like staircase) and kinocilium (taller)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Deflection toward kinocilium

A

Depolarization of hair cell membrane –> exocytosis –> excites distal process of auditory nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Deflection away from kinocilium

A

Hyperpolarization of hair cell membrane –> less signal –> inhibits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Basilar membrane is wider and more flexible at the _______ for which kind of tones? And the converse? What is this called?

A

Apex = low tones; narrower and more rigid at base = high tones; tonotopic organization of basilar membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a special function of the outer hair cells? What are they vulnerable to?

A

Amplify movement of basilar membrane in response to low intensity sounds; vulnerable to aminoglycoside antibiotics (ototoxic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Steps of hearing after hair cells

A
  1. Inner hair cells activate distal process of auditory nerve; 2. Cell bodies of auditory nerve fibers are located in Spiral Ganglion; 3. Proximal processes of auditory nerve enter brainstem and pontine-medullary junction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Projection pathway of auditory system

A

Cochlear nuclei (located lateral to inferior cerebellar peduncle) –> superior olive (some crossing here) –> inferior colliculus –> medial geniculate body (thalamus) –> auditory cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Superior olive is responsible for…how? Fibers from here ascend in what tract? What other fiber tract projects from here?

A

Horizontal localization of sound because it receives binaural input from cochlear nuclei; calculate interaural intensity (loudness) and timing differences; lateral lemniscus; also sends a projection back to outer hair cells via olivocochlear bundle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Input from olivocochlear bundle does what? (2)

A

Selective auditory attention when there is background noise, protection from loud noise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where do we find the medial geniculate nuclei?

A

Hanging off the thalamus at the level of the midbrain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Were does the medial geniculate nucleus project?

A

NOT through internal capsule, but sneak behind posterior limb of IC through the auditory radiation and synapse at Heschl’s gyri

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Describe Heschl’s gyri tonotopic organization

A

Anterior –> low, Posterior –> high frequency (corresponding apex –> base)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What else does the auditory cortex convey?

A

What and where sound information

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Newborn hearing test looks for (2)

A

Otoacoustic emissions (haircell dance) and auditory brainstem responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What two important pieces of information are conveyed by the peripheral vestibular system?

A
  1. Angular acceleration of the head; 2. Linear acceleration of the head (up and down)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Vestibulo-thalamo-cortical pathway does what? What thalamic nucleus? To where in cortex?

A

Conscious perception of equilibrium; VP nucleus (contralateral); posterior parietal cortex (primary vestibular cortex)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Vestibulo-ocular reflex (VOR). Afferent and efferent limb?

A

Steady gaze during head movement; afferent limb = vestibular, efferent limb = oculomotor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Vestibulo-spinal tracts: what two functions and what are their pathways? Ipsi/bilateral?

A

Postural equilibrium: lateral tract, sends input down spinal cord to innervate motor neurons to extensor musculature (ipsilateral); head stability during body movement: medial tract (vestibulo-colic pathway) maintains head stability during body movement through MLF to cervical spinal cord (bilateral)

33
Q

Vestibulo-autonomic reflex. Test? Describe.

A

Effects compensatory changes in BP, respiration and digestion with changes in posture; tilt table test, normal = increased BP when table titled 70 degrees vertically, orthostatic hypotension is a drop in BP when table is tilted

34
Q

Components of peripheral sensory apparatus (labyrinth)

A

Semicircular canals, otolith organs

35
Q

Components of the central pathways of the vestibular system

A

Four vestibular nuclei; projections to the thalamus, oculomotor neurons, spinal cord, brainstem; reciprocal connections with cerebellum

36
Q

Semicircular canals: function and names

A

Detect angular head acceleration; anterior/superior, posterior/inferior, lateral/horizontal

37
Q

Otolith organs: function and components

A

Detect linear acceleration of the head; utricle and saccule

38
Q

Similar to the auditory system, the bony cavities of the vestibular system and filled with _________, while the membranous sacs are filled with __________

A

Perilymph, endolymph

39
Q

Swelling at semicircular canals called. What is inside this? What is this made of?

A

Ampulla; Crista ampullaris = receptor sheet for semicircular canals; hair cells! with the same excitation/inhibition pattern as auditory system

40
Q

What are hair cells sensitive to? (3)

A

Trauma, aminoglycoside toxicity, and aging

41
Q

What is different about the hair cells in the semicircular canals, as compared to the those in the cochlea?

A

Lodged in the gelatinous cupula (not tectorial membrane)

42
Q

Clinicians have defined how many planes of movement for the canals? Describe

A

Three: horizontal, RALP, LARP

43
Q

Saccule detects…

A

Linear acceleration/displacement in vertical plane

44
Q

Utricle detects…

A

Linear acceleration in horizontal plane

45
Q

Sensory sheets in otolith organs are called…hairs protrude into…comprised of?

A

Macula; otolithic membrane; gelatinous structure and otoconia (calcium carbonate crystals)

46
Q

How is tilt detected in otolithic membrane?

A

Shifting heaviness of otoconia

47
Q

Hair cells of the vestibular system synapse on…cell bodies where? Synapses where? How many?

A

Distal processes of VIII; Scarpa’s Ganglion; vestibular nuclei (4)

48
Q

Vestibulo-colic reflex does what?

A

Maintains head stability during body movement (keeps head upright)

49
Q

Vestibular evoked myogenic potentials (VEMPS) tests what? Describe.

A

Tests otolith function. Apply sound to patient –> vestibular nuclei –> medial/lateral vestibulospinal tract –> record myogenic potential on neck attributable to sound.

50
Q

Two types of hearing loss and regions of the ear they affect

A

Conductive loss (outer –> middle ear) and sensorineural hearing loss (SNHL; inner ear –> CNS)

51
Q

Weber test assesses which type of hearing loss? How? What if they have SNHL?

A

Conductive: sound lateralizes to ear with conductive hearing loss; lateralizes AWAY from SNHL

52
Q

If someone has SNHL, what will happen in the Rinne test? What if they have conductive hearing loss?

A

SNHL = normal test, air louder than bone; Conductive = positive test, bone louder than air

53
Q

What does an audiogram assess? (3)

A

Pure tone threshold for air and bone, and speech reception, speech discrimination

54
Q

What does tympanometry assess?

A

Movement of ear drum: assesses middle ear pressure

55
Q

How do you screen hearing in newborns? What’s the next test?

A

Otoacoustic emissions; auditory brainstem response

56
Q

Causes of conductive hearing loss (6)

A

Cerumen, eustachian tube swelling, tympanic membrane perforation, excess fluid, cholesteatoma, or an ossicular abnormality

57
Q

Name and describe an ossicular abnormality and treatment

A

Otosclerosis: fixation of stapes bone; staepectomy

58
Q

Causes of sensorineural hearing loss (6)

A

Noise, age, genetics, toxins, virus and acoustic neuroma

59
Q

T/F: SNHL is usually bilateral

A

True! (except for Meniere’s or acoustic neuroma)

60
Q

Hearing loss of age

A

Presbycusis

61
Q

What is an acoustic neuroma?

A

Benign tumor of the schwann cells of the vestsibulochoclear nerve

62
Q

Who would get a cochlear implant?

A

Severe bilateral SNHL in an adult or child who has had no benefit from hearing aid

63
Q

Four-step approach to the dizzy patient

A
  1. Understand vestibular physiology; 2. Classify the complaint using history; 3. Peripheral (ENT, labyrinth) or central (neurological); 4. Know the common vestibular syndromes
64
Q

Classifying dizziness and common causes (3)

A
  1. Vertigo = false sense of motion (vestibular); 2. Imbalance/disequilibrium (vestibular, visual, proprioceptive, CNS [cerebellar, etc.]); 3. Lightheadedness (cardiovascular/metabolic)
65
Q

What test measures eye movement?

A

VNG Videonystagmography

66
Q

In a peripheral vestibular lesion, nystagmus is seen away/toward lesion

A

Away

67
Q

Five common vestibular syndromes

A

Acute, unilateral vestibular loss, Meniere, BPPV, bilateral vestibular loss, migraine-associated dizziness

68
Q

Acute unilateral vestibular loss presents with (4)…prognosis? Common causes (4)

A

Sudden onset of vertigo, N/V, nystagmus, Romberg; good; infection, neuroma, injury, infarction

69
Q

Meniere’s syndrome presents with…

A

Episodic vertigo, N/V, unilateral hearing loss (w/ tinnitus)

70
Q

What is the pathophysiology of benign positional paroxysmal vertigo (BPPV) and what does this cause? Treatment?

A

Dislodging of otoconia; acute vertigo brought on by positional change and rotary nystagmus elicited by Dix-Hallpike maneuver; particle repositioning

71
Q

Four common causes of central vertigo

A

Cerebellopontine angle tumor, stroke, migraine, MS

72
Q

T/F: Hearing loss is common with central vertigo

A

False!

73
Q

In central vertigo, nystagmus is/is not inhibited by fixation of eyes onto an object

A

NOT

74
Q

Bilateral vestibular loss can be caused centrally/peripherally/both

A

Both

75
Q

What are some causes of bilateral vestibular loss (5)? Symptoms? Prognosis?

A

Aminoglycoside or other toxicity, age related factors, infections, trauma, inflammatory/autoimmune conditions; ataxia + oscillopsia (the illusion that the environment is moving when we move our heads) but NO VERTIGO; prognosis = poor

76
Q

In bilateral vestibular vertigo, what happens with caloric response?

A

Absent in both ears

77
Q

Unilateral deafness must be due to damage to what structures. Why?

A

Ear, auditory nerve, or cochlear nuclei (nothing higher); after the nuclei, all tracts carry bilateral information

78
Q

All five functional pathways of the vestibular system are under control of this structure.

A

The cerebellum

Brain and Behavior (56 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions