auditory

Question 1

What is the visible external part of the ear called?

Answer 1

Pinna (auricle)

Question 2

What structures shape the ear and are vulnerable to hematomas?

Answer 2

Auricular cartilage

Question 3

What is the function of the external auditory canal?

Answer 3

leads to the tympanic membrane; conducts sound

Question 4

What is cerumen?

Answer 4

Waxy secretion (earwax) from sebaceous and ceruminous glands

Question 5

What does the tympanic membrane separate?

Answer 5

External and middle ear

Question 6

What are the auditory ossicles?

Answer 6

What are the auditory ossicles?

Question 7

What muscle tenses the tympanic membrane and what nerve innervates it?

Answer 7

Tensor tympani m. , CN V

attached to malleus

Question 8

What muscle dampens loud vibrations and what nerve innervates it?

Answer 8

Stapedius, CN VII - facial

decreases movement of stapes

Question 9

What is the function of the auditory (Eustachian) tube?

Answer 9

Equalizes pressure between middle ear and nasopharynx

Question 10

Where is the cochlea located?

Answer 10

in the petrous temporal bone of the inner ear

Question 10

what fluid fills the membranous labyrinth?

Answer 10

endolymph

Question 11

what fluid fills the bony labryrinth?

Answer 11

perilymph

Question 12

What structure contains hair cells that transduce sound?

Answer 12

Spiral organ (Organ of Corti)

Question 13

What is the role of the stria vascularis?

Answer 13

Produces endolymph and trophic factors via melanocytes

Question 14

What does the cochlear nerve join to form?

Answer 14

Vestibulocochlear nerve (CN VIII)

Question 15

How is sound transmitted to the cochlea?

Answer 15

Pinna → tympanic membrane → ossicles → oval window → cochlea

Question 16

Pinna → tympanic membrane → ossicles → oval window → cochlea

Answer 16

Basilar membrane moves → hair cell cilia bend → depolarization → glutamate release → cochlear nerve activation

Question 17

What is the auditory pathway to the cortex?

Answer 17

Cochlear nerve → cochlear nuclei → trapezoid body → lateral lemniscus → caudal colliculi → medial geniculate nucleus → auditory cortex

Question 18

Why don’t central lesions usually cause complete deafness?

Answer 18

Because both ears project bilaterally to the cortex

Question 19

What causes congenital deafness in animals with merle coats?

Answer 19

Absence of melanocytes in stria vascularis → hair cell degeneration

Question 20

What are the types of deafness?

Answer 20

Conduction, Sensorineural, Mixed

Question 21

What is conduction deafness?

Answer 21

Impaired transmission of sound (e.g., otitis externa)

Question 22

What is sensorineural deafness?

Answer 22

Damage to hair cells or cochlear nerve (e.g., merle-linked, or ototoxic drugs)

Question 23

What is the main test for diagnosing deafness in animals?

Answer 23

what is the main test for diagnosing deafness in animals?

Question 24

What does BAEP/BAER evaluate?

Answer 24

Auditory nerve and brainstem pathway function, localizing sedated test using electrodes and clicks

Question 25

What is a common cause of ototoxicity?

Answer 25

Aminoglycosides like gentamicin or neomycin

Question 26

How do ototoxic drugs cause deafness?

Answer 26

They damage hair cell membranes and mitochondria

Question 27

How do animals localize sound?

Answer 27

Interaural time and intensity differences; pinna positioning

Question 28

What feature helps owls localize sound vertically?

Answer 28

Offset ear positions

Question 29

Which membrane supports the hair cells of the cochlea?

Answer 29

Basilar membrane

Question 30

Which auditory structure equalizes air pressure?

Answer 30

Eustachian tube

Question 31

spiral ganglion

Answer 31

contains afferent neuron' cell bodies

Question 32

tectorial membrane

Answer 32

Rigid; hair cell cilia bend against it to initiate depolarization.

Question 33

describe how sound is transmitted to the cochlea

Answer 33

1. pinna captures air pressure waves 2. tympanic membrane vibrates 3. vibrations transmitted via ossicles (malleus--> incu--> stapes 4. stapes footplate vibrates against the vestibular window 5. pressure waves enter perilymph in scala vestibuli 6. vibrations transmitted through cochlear duct--> basilar membrane 7. basilar membrane movement causes cilia bending in hair cells 8. cilia movement against tectorial membrane --> depolarization 9. hair cells release glutamate --> stimulate cochlear nerve

Question 34

describe how cochlear input is transmitted to the auditory cortex

Answer 34

1. cochlear nerve (CN VIII) enteres brainstem at medulla-pons junction 2. synapses in cochlear nuclei 3. second- order neurons decussate via TRAPEZOID BODY, ascend bilaterally via LATERAL LEMNISCUS 4. project to caudal colliculi (midbrain) 5. medial geniculate nucleus (thalamus) 6. primary auditory cortex ( sylvian and ectosylvian gyri of temporal lobe

Question 35

central lesion rarely cause complete deafness unless....

Answer 35

both sides are affected

Question 35

bilateral projections ensure.....

Answer 35

both ears contribute to both cortices

Question 36

coat color genetics

Answer 36

merle - dogs piebald - various species white cats with blue eyes

Question 37

mixed deafness

Answer 37

age related - presbycusis ossicle and receptor degeneration

Question 38

what structure transduces sound vibrations into electrical signals

Answer 38

hair cells in the spiral organ (organ of corti)

Question 39

what mechanism causes congenital deafness in piebald animals?

Answer 39

absence of melanocytes in stria vascularis --> hair cell death

Question 40

which membrane supports the hair cells of the cochlea?

Answer 40

basilar

Question 41

which auditory structure is responsible for equalizing air pressure?

Answer 41

eustachian tube

Question 42

BAEP testing is used to evaluate

Answer 42

auditory nerve and brainstem pathways

Question 43

a lesion in the right auditory cortex would result in

Answer 43

mild hearing deficit due to bilateral input

Question 44

manubrium mallei

Answer 44

handle of malleus

Question 45

cochlear window

Answer 45

round window

Question 46

vestibular window

Answer 46

oval window

Question 47

what protective functions does the ear have?

Answer 47

tensor tympani m. and stapedius m. (decreases movement of stapes)