Auditory and Vestibular System ppt 26

Question 1

What are the anatomical components of the middle ear?

Answer 1

Auditory ossicles:Transmit and amplify vibrations from tympanic membrane to oval window.

Auditory (eustachian) tube:Equalizes air pressure on both sides of tympanic membrane.

Question 2

What are the anatomical components of the internal ear?

Answer 2

Cochlea: Contains a series of fluids, channels, and membranes that transmit vibrations to spiral organ (organ of Corti), the organ of hearing; hair cells in spiral organ produce receptor potentials, which elicit nerve impulses in cochlear branch of vestibulocochlear (VIII) nerve.

Question 3

What is the mechanism of sounds conduction

Answer 3

mechanical movement of stereocillia causes depolarization of hair cells.

a downward displacement causes hyperpolarization

Question 4

What is the auditory pathway?

Answer 4

Cochlear nerve–> cerebellopontine angle (lateral pons)–> superior olivaery, trapezoid, l. lemmiscus, inf. colliculus, medial geniculate body, super temporal gyrus

Question 5

What is the tympanic reflex?

Answer 5

Tensor tympani and stapedius muscles cause the malleus be pulled inward

Question 6

What is the issue with a Eustachian tube dysfunction?

Answer 6

altered pressure= TM stretch= pain

Question 7

What is a conduction deafness hearing defect?

Answer 7

interruption of the passage of sound waves through the external or middle ear

Obstruction
Ostoclerosis
Otitis Media (inflammation)

Question 8

What is a nerve deafness hearing defect?

Answer 8

Disease of the cochlea, cochlear nerve, or central auditory pathway (acoustic neuroma)

Presbycusis (aging. most common cause of hearing loss)
Acoustic Neuroma

Question 9

Weber Test

Answer 9

Tunning fork top head

unilateral louder sound sound:
conduction-bad ear
sensorineural- good ear

Question 10

Rinne Test

Answer 10

A>B

air/ bone conduction

Question 11

Schwabach Test

Answer 11

compares bone conduction to a normal person

Question 12

What are the anatomical components of the vestibular apparatus?

Answer 12

Semicircular ducts.
Otolithic Organs (saccule and utricle)

Question 13

What is the function of the semilunar ducts?

Answer 13

Contain crustal (hair cells) that respond to rotational Acceleration and declaration of movement,

Question 14

What is the function of the utricle?

Answer 14

horizontal acceleration

static equilibrium in relation to the force of gravity. most sen. when head is up right

Question 15

What is the function of the saccule?

Answer 15

vertical acceleration

static equilibrium in relation to the force of gravity. most sen. when head is horizontal

Question 16

What kind of crystals lie atop hair cells in the otolithic organs?

Answer 16

Calcium Carbonate crystals called otoconia

Question 17

What are the fluids of the labyrinth?

Answer 17

Perilymph-Extracellular fluid:communicates with subarachnoid via aqueduct

Endolymph-Intrecellular fluid: recreated by the stria

Question 18

What is the role of vestibular apparatus in posture?

Answer 18

• maintenance of equilibrium & balance.
• hair cells in vestibular apparatus activates VIII.
• Sensory fibers transmit impulses to cerebellum

Question 19

What is the 3 neuron arc in the VOR

Answer 19

oculomotor nuclei, vestibular nuclei, and vestibular ganglion.

Question 20

Caloric Nystagmus

Answer 20

Mnemonic COWS Cold, Opposite; Warm, Same

watch vide

Question 21

Internuclear opthalmoplegia

Answer 21

definite in adduction and contralateral abducting nystagmus

horizontal diplopia
trouble tracking fast objects

watch video: https://www.youtube.com/watch?v=MWJz75R01s4

Question 22

Motion sickness

Answer 22

caused by stimulation of the semicircular canals during motion,

ntihistamines that affect the neural pathways from the vestibule.

Question 23

Meniere Disease

Answer 23

an inner ear disease associated with an increase in endolymphatic fluid pressure. Characterized by episodic attacks of vertigo, tinnitus, hearing loss, horizontal nystagmus

Question 24

Tinnitus

Answer 24

• noises such as ringing, clicking, whistling, or booming in the ears.
• disorders in the middle or inner ear

Question 25

Vertigo

Answer 25

• sensation of turning or rotation
• nausea, vomiting, and gait ataxia.

-lesions that affect the labyrinth of the inner ear or the vestibular division of CN VIII.