Ear anatomy and hearing

Describe anatomy of outer ear

flap - pinna

Describe location and anatomy of middle ear

area between the ear drum and the oval window is called the middle ear

consists of tympanic membrane, malleus, incus, stapes.

What is another name for inner ear?

cochlea

Name the three chambers of the cochlea

scala vestibule, scala media and scala tympani

what is perilymph

normal tissue fluid found in scala tympani

what is endolymph and what are its properties

unusual tissue fluid found in scala media

has:

• high conc of K+, low NA+ conc

• positive membrane potential

what is the organ of corti

receptor organ for hearing, locating in the cochlea (inner ear)

Label the components of the organ of corti

A- tectorial membrane

B- sensory hairs

C- basilar membrane

D- outer hair cells

E- inner hair cell

explain the basic mechanism of hearing

sound waves caught by outer ear

travel to middle ear

Sound waves vibrate oval window

wave travels along basement membrane

hair cells squished against non-moving tectorial membrane

hair cells generate electrical signal

What type of innervation does the organ of corti have

what cranial nerve are these associated with

Afferent and Efferent

VIII - vestibulocochlear

outline auditory pathway from ear to cortex

Cochlea - brainstem (caudal colliculus) - thalamus (medial geniculate nucleus) - cortex (auditory cortex)