organ of Corti; spiral organ

Function

• the sensory organ of hearing
• it is the site of transduction of mechanical energy into neural signaling

Structure

• a prominent ridge of highly specialized epithelium in the floor of the cochlear duct overlying the basilar membrane of the cochlea
• it extends spirally from the basal convolution to the cupula or apex of the cochlea.

It contains:

• hair cells (post mitotic)
  • 1 layer of inner hair cells
  • 3 layers of outer hair cells
• supporting columnar cells
  • pillars of Corti
  • phalangeal cells of Deiter
  • cells of Henson
  • cells of Claudius
• Reissner's membrane
• tectorial membrane
• stria vascularis

Pathology

• age-related degeneration of the Organ of Corti gives rise to age-related hearing impairment
• loss of hair cells is greatest in persons > 70 years of age.
  • outer hair cells are more vulnerable than inner hair cells
  • loss of hair cells occurs preferentially in the basal region of the cochlea & accounts for the loss of pure-tone hearing.

More general terms

• ear structure

Component of

• cochlea

Components

• phalangeal cell of Deiter
• cell of Henson