A&P2 Hearing(Anatomy)

Name the parts of the outer ear we need to know. What does the auricle do?

Auricle(pinna): collects sound noise into inner ear canal

External Acoustic Meatus: tube structure connecting auricle to tympanic membrane(eardrum) allowing sound waves to travel to the eardrum

Tympanic membrane: thin membrane separating outer ear from middle ear vibrating when hit by sound waves transmitting them to middle ear ossicles

Name the part of the ear that vibrates?

tympanic membrane (eardrum)

Name the part of the middle ear.

-Tympanic membrane

-Ossicles: malleus(hammer), Incus(anvil), Stapes(stirrup)

-Eustachian Tube (Auditory Tube)

1) 3 ossicles? Arrangement?

1.Malleus picks up vibrations from eardrum transmitting them to the incus

2.Incus acts as bridge between malleus and stapes passing the received vibrations to stapes

3. Stapes connect to oval window (entrance to cochlea) transmitting sound waves into cochlea from vibration and then processed into nerve signals for the brain.

Purpose of Eustachian tube?

Also known as the auditory tube the eustachian tube equalizes air pressure as well as draining fluids

What parts are used in balance? Hearing?

Inner Ear:

Cochlea- Hearing

Vestibule- Balance/head movement

Semicircular canals- Balance/detect rational movement Membranous labyrinth- endolymph

Bony labyrinth- perilymph

Where is perilymph found? Endolymph? Which has a high k+ content?

Inner ear:

Perilymph is found in the scala vestibuli and scala tympani of cochlea- low k+

Endolymph is in the cochlear duct- high k+

What is the organ of Corti (spiral organ)? What are some of the hair cells embedded in?

-The sensory organ responsible for converting sound vibrations into sound sending signals to the brain

-Sensory hair cells: Inner hair cells and outer hair cells

What part of the cochlear duct is the organ of Corti found?

Located in the cochlear duct in the scala media