Question

Write short note on cochlea.

Answer 1

The cochlea is a long, coiled outgrowth of sacculus. It is the main hearing organ. The cochlea forms three chambers:

(i) Upper − scala vestibule

(ii) Middle − scala media

(iii) Lower − scale tympani

The floor of the scala media is basilar membrane while its roof is Reissner’s membrane. Reissner’s membrane gives out a projection called as the tectorial membrane. The organ of Corti, a hearing organ, is located on the basilar membrane. Organ of Corti contains receptor hair cells. The upper scala vestibule and lower scala tympani contain perilymph.