Mechanism Of Hair Cell

Excitation

It is the receptor organ for hearing and is located in the mammalian cochlea.

ORGAN OF CORTI

Structure of organ of corti

• Receptor organ• Single row of INTERNAL

HAIR CELLS• 90-95% cochlear nerve

endings terminate on inner hair cells (detection of sound)

• 3 or 4 rows of OUTER HAIR CELLS

transmit the auditory signals to CNS

Control the sensitivity of inner hair cells at different sound pitches called

as Tuning of the receptor system.

Reticular laminaStereociliaTectorial

membraneTriangular rods

of Corti

Basilar fibers

Single Hair Cell Structure

The hair cells of the organ of Corti may have about 100 tiny stereocilia which in the resting state are leaning on each other in a conical bundle.

In response to the pressure variations in the Cochlea produced by sound, the stereocilia may dance about wildly and send electrical impulses to the brain.

At Rest Depolarization Hyperpolarization