ALMOST FINISHED Auditory System

Question 1

What are the three ossicles of the middle ear?

Answer 1

Malleus, incus, and stapes

Question 2

What is the function of the tensor tympani muscle?

Answer 2

Dampens low tones by pulling on the malleus internally, thereby increasing the tension on the tympanic membrane

Question 3

The tensor tympani is innervated by which nerve?

Answer 3

CN V

Question 4

What is the function of the stapedius muscle?

Answer 4

Decreases sound intensity by pulling the stapes away from the opening into the inner ear

Question 5

What are the two openings between the cochlea and the middle ear?

Answer 5

Oval window and round window

Question 6

The oval window opens into what structure of the cochlea?

Answer 6

Scala vestibuli

Question 7

The round window opens into what structure of the cochlea?

Answer 7

Scala tympani

Question 8

The stapedius muscle is innervated by which nerve?

Answer 8

CN VII

Question 9

What structure separates the scala vestibuli and cochlear duct?

Answer 9

Vestibular membrane (Reissner membrane)

Question 10

What structure separates the scala tympani and the cochlear duct?

Answer 10

Basilar membrane

Question 11

At what portion of the spiral organ do hair cells respond to high frequency sounds?

Answer 11

Near the base

Question 12

At what portion of the spiral organ do hair cells respond to low frequency sounds?

Answer 12

Near the apex

Question 13

Why does damage to CN VII cause hyperacusis?

Answer 13

Loss of function of the stapedius muscle, which decreases sound intensity

Question 14

The auditory pathways consist of which five structures?

Answer 14

Spiral ganglion, cochlear nuclei, superior olivary nucleus, inferior colliculys, and the medial geniculate nucleus

Question 15

Where do the auditory pathways terminate?

Answer 15

Transverse temporal gyrus of Heschi

Question 16

Damage to which portion of the auditory pathways result in ipsilateral hearing deficits?

Answer 16

Cochlea, spiral ganglion, cochlear nerve, or cochlear nuclei

Question 17

Lesions above the cochlear nuclei result in what kind of hearing alterations?

Answer 17

Poor sound localization, but bilateral hearing remains intact (only mild deficits)

Question 18

What are the common causes of conduction hearing loss?

Answer 18

Infection, congenital, foreign body or wax, perforated eardrum, otosclerosis, and cholesteatoma

Question 19

What is conduction hearing loss?

Answer 19

Interference with sound wave passage through external or middle ear

Question 20

What is sensorineural hearing loss?

Answer 20

Damage to inner ear (hair cells, cochlear nerve, etc.)

Question 21

What is otosclerosis?

Answer 21

Overgrown of the stapes bone, which interferes with its connection to the oval window

Question 22

What is a cholesteatoma?

Answer 22

Overgrown of keratin debris in the middle ear space, which may erode internal structures

Question 23

What aspect of hearing is tested with the Rinne test?

Answer 23

Conduction

Question 24

What aspect of hearing is tested with the Weber test?

Answer 24

Localization

Question 25

What Rinne test results do you see in a person with normal hearing?

Answer 25

Air > bone

Question 26

What Weber test results do you see in a person with normal hearing?

Answer 26

Midline

Question 27

What Rinne test results do you see in a person with sensorineural hearing loss?

Answer 27

Air > bone, but not as loudly in affected ear

Question 28

What Weber test results do you see in a person with sensorineural hearing loss?

Answer 28

Sound localizes to normal ear

Question 29

What Rinne test results do you see in a person with conductive hearing loss?

Answer 29

Bone > air

Question 30

What Weber test results do you see in a person with conductive hearing loss?

Answer 30

Sound localizes to affected ear

Question 31

What are the common causes of sensorineural hearing loss?

Answer 31

Loud noise, head trauma, viral, autoimmune, antibiotics, diuretics, Meniere disease, presbycusis, tumors (acoustic neuroma)

Question 32

What are the two common causes of peripheral vertigo?

Answer 32

Meniere disease and benign paroxysymal postural vertigo

Question 33

What is the pathophysiological mechanism of Meniere disease?

Answer 33

Peripheral vestibular and auditory apparatus is damaged by increased endolymphatic pressure, which gradually destroys hair cells in the vestibular and auditory peripheral systems

Question 34

What are the symptoms of Meniere disease?

Answer 34

Abrupt attacks of severe vertigo with nausea and vomiting, tinnitus, and progressive sensorineural deafness

Question 35

What is the treatment for Meniere disease?

Answer 35

Diuretics, low sodium diet, anti-histaminics

Question 36

What is the pathophysiological mechanism of BPPV?

Answer 36

Otoconia are displaced from the urticle or saccule into the semicircular canals, interfering with the macula and causing vertigo

Question 37

What is the treatment for BPPV?

Answer 37

Epley maneuver