Anatomy of Auditory System: Inner Ear

Another name for the inner ear

labyrinth

Where is the inner ear located?

temporal bone

Parts of inner ear

vestibule, semicircular canals, cochlea

Important holes in inner ear?

oval window and round window

oval window

where the stapes connects to the inner ear

round window

a membrane-covered hole that allows the fluids in the cochlea to move

cochlea contains

organ of corti

semicircular canals and vestibule contain

organs of balance (macculae &cristae)

describe outside and inside of labyrinth

The inner ear consists of a bony labyrinth (outer shell) and membranous labyrinth (within)

bony labyrinth

filled with perilymph

membranous labyrinth

filled with endolymph

Widest part of the cochlea

base

the narrowest part of cochlea

apex

Cochlea's bony core

modiolus

bony shelf that projects from the modiolus

spiral lamina

The membranous labyrinth splits the cochlea into three compartments, or channels:

-Scala vestibuli -Scala tympani -Scala media

Scala Vetibuli

is contiguous with the vestibule at the base of the cochlea.

scala tympani

The scala tympani ends at the middle ear wall where the round window is located.

scala media

The scala media connects to the scala tympani at the helicotrema located at the apex of the cochlea.

the primary membranes that divide the cochlea into three channels are

Reissner's membrane and the basilar membrane.

Reissner's membrane

separates the scala vestibule from the scala media

is attached to spiral limbus

basilar membrane

separates the scala tympani from the scala media.

is attached to the spiral lamina and spiral ligament

organ of corti is also known as

organ of hearing

The stria vascularis is located

on the outside edge of the scala media

The tectorial membrane is attached to

the spiral limbus and extends out over the organ of Corti

what are sensory cells that change mechanical motion into electrochemical impulses?

Hair cells

hair cells contain

stereocilia (tiny hairs)

The stereocilia are attached to the hair cell at

the cuticular plate

what contains hair cells and support cells

organ of corti

Inner Hair Cells (IHC)

1 row

Outer Hair Cells (OHC)

3 rows

IHC shape

U shaped

OHC shape

V or W shaped

Stereocilia are connected by cross-links

Side to side

Row to row

Tip to side (also known as tip links)

Tip links control

ion channnels

organ of corti support cells help form

reticular lamina

reticular lamina

A barrier at the top of the body of the hair cells and support cells

Keeps endolymph and perilymph from mixing