Q.Name the three main parts of the human ear.

The human ear serves both hearing and balance, and is divided into three parts. The outer ear (pinna and external auditory canal) collects sound and channels it to the tympanic membrane (eardrum). The middle ear, an air-filled cavity linked to the pharynx by the Eustachian tube (which equalises air pressure across the eardrum), contains three ossicles — malleus, incus and stapes — that mechanically amplify vibrations from the eardrum and pass them to the oval window. The inner ear contains the fluid-filled, coiled cochlea, where vibrations stimulate hair cells in the organ of Corti to generate nerve impulses carried by the auditory nerve to the auditory cortex; and the vestibular apparatus (utricle, saccule and three semicircular canals), which detects linear and rotational head movement and, via the vestibular nerve, allows the brain (especially the cerebellum) to maintain balance and posture.