Auditory System

Question 1

three regions of the ear

Answer 1

• external ear
• middle ear
• inner ear

Question 2

components of the external ear

Answer 2

• auricle
• external auditory meatus
• tympanic membrane

Question 3

auricle

Answer 3

• S-shaped tube
• outer 2/3 is made of elastic cartilage
• inner 1/3 is made of bone

Question 4

external auditory meatus location

Answer 4

-opening in temporal bone

Question 5

external auditory meatus components

Answer 5

• hairs and glands

- cerumen

Question 6

hairs and glands location/function

Answer 6

• on outer portion of sebaceous glands

- produces oil to lubricate hair and collect dust

Question 7

cerumen

Answer 7

• aka ear wax
• waxy substance secreted by glands in outer ear
• repels insects

Question 8

tympanic membrane**

Answer 8

• aka eardrum
• separates the outer ear from middle ear
• very thin membrane
• vibrates when hit by sound waves

Question 9

middle ear components

Answer 9

• tympanic cavity
• auditory (eustachian tube)
• ossicles (small bones)

Question 10

tympanic cavity

Answer 10

-lined with mucous cells

Question 11

eustachian tube**

Answer 11

-connects nasopharynx with middle ear

Question 12

ossicles components

Answer 12

• malleus
• incus
• stapes

Question 13

malleus

Answer 13

-attached to tympanic membrane

Question 14

incus

Answer 14

-interposed between malleus and stapes

Question 15

stapes

Answer 15

-inserted into oval window of inner ear

Question 16

inner ear function

Answer 16

-has receptors for hearing and equilibrium

Question 17

which cranial nerve transmits the receptor impulses to the brain for interpretation?

Answer 17

-vestibulocochlear nerve

Question 18

what is the inner ear also called?

Answer 18

-labrynth

Question 19

inner ear inner membranous cavity and tube fluid components

Answer 19

• perilymph

- endolymph

Question 20

perilymph

Answer 20

-surrounding water

Question 21

endolymph

Answer 21

-inner water

Question 22

inner ear components

Answer 22

• cochlea
• vestibule
• semicircular canals

Question 23

cochlea structure

Answer 23

• spiraling chamber in body labyrinth (“snail”)

- used for hearing

Question 24

cochlea components

Answer 24

-organ of corti

Question 25

organ of corti

Answer 25

• located in inner ear

- “hair cell” receptors for hearing

Question 26

auditory pathway

Answer 26

-cochlear division of CN VIII–> nucleus of CN VIII in medulla–> thalamus–> auditory cortex of temporal lobe (area 41,42)

Question 27

vestibular apparatus components

Answer 27

• semicircular canals

- utricle and saccule

Question 28

semicircular canals

Answer 28

• three horse shoe shaped structures arranged at different angles filled w fluid
• motion of head moves hair cells, creating electrical impulse conducted to brain
• important for dynamic equilibrium(i.e. spinning)

Question 29

utricle and saccule

Answer 29

• bulging chambers in vestibule containing fluid and hair cells w suspended crystals (aka otolins)
• motion causes crystals to move the hair cells, creating electrical impulse
• important for static equilibrium(activated in acceleration; i.e. car, elevator)

Question 30

vestibular pathway

Answer 30

-vestibular division of CN VIII–> vestibular nuclei of pons and medulla–> cerebral cortex