SLH 306K unit 2 parts of ear!

unfinished

Auricle (where and what)

Outer Ear

cartilage flap, funnels sound waves

Auditory canal

Outer ear between auricle and eardrum

funnels sound waves, auditory meatus excretes cerumen for protection

Tympanic membrane

outer ear, bordering middle ear

concave, and drumlike

includes par flaccida (flaccid), pars tensa (tense), and cone of light

Ossicular Chain (ossicles)

Middle ear

amplifies waves

Malleus: connected to the tympanic membrane and incus

Incus: connected to malleus and stapes

Stapes: moves in and out of the oval window

Eustachian Tube

middle ear

connects the air-filled middle ear to an opening in the upper back portion of the throat

Semicircular canals

Inner ear

fluid filled, used for balance and positioning urself in space

vestibular system

Vestibule

Inner ear

sense of balance

vestibular system

Cochlea

inner ear

sense of hearing (auditory system)

coiled around bony axis called modiolus

What’s inside of the cochlea??

scala vestibuli, scala media (cochlea duct), scala tympani

reissner’s membrane, basilar membrane

organ of corti

what parts of the ear are tonotopic?

organ of corti, and the hair cells in it

tonotopic definition: high pitches are at beginning of membrane and low pitches are at end of membrane

structure of hair cells in organ of corti

3 outer hairs, and 1 inner hair closest to modiolus in one row

tectorial membrane on top of hair cell physically opens gate on hair cells and depolarizes cell

perilymph (where and what)

cochlea

fluid in scala vestibuli and scala tympani

endolymph

cochlea

fluid in scala media (cochlea duct)

oval window

middle ear

the stapes fits into this window perfectly

afferent nerve

a neuron that sends signals from cochlea to brain

efferent nerves

neuron sends signals from brain to cochlea