The ear performs the functions of hearing and balance.
(a) Hearing: (i) The sound waves collected by external ear passes through the external auditory meatus to
the tympanic membrane which vibrates.
(ii) The vibrations are transmitted across the I middle ear by malleus, incus and stapes
(iii)The perilymph of the internal ear receives the vibrations through the membrane covering, from here they are transferred to the scala vestibuli of cochlea and then to scala media.
(iv) Therefore, the movements of endolymph and tectorial membrane stimulates the sensory hairs of the organ of corti which carried the impulses to the brain through auditory nerve where the sensations of hearing is felt.
(b) Equilibrium : (i) The semicircular canals, utriculus and sacculus of membranous labyrinth are the structures of equilibrium.
(ii) Whenever the animal gets displaced the hair cells of the cristae and maculae are stimulated by the movement of the endolymph and otolith.
(iii) The stimulus are carried to the brain through
auditory nerve and the change of the position is detected by medulla oblongata of the brain, the brain sends impulses to the muscles to regain the normal conditions.