Describe the structure and functions of the various parts of the mammalian ear - KCSE Biology Essay

Pinna; is wide/funnel-shaped to collect/gather sound waves; and direct them to the auditory canal into the ear;

Eardrum/tympanic membrane is thin and light; to convert sound waves into vibrations;

Ear ossicles/maleus, incus and stapes are of high density; to magnify/amplify sound waves;

Oval window is smaller than eardrum; to magnify the sound waves; and direct them to the inner ear;

Cochlea is long and coiled; to increase surface area; for attachment of receptor cells/sensory hairs; cochlea has many sensory hairs; which receive sound vibrations and generate impulses;

Liquid or fluid/endolymph in cochlea; transmit sound vibrations;

Auditory nerve; transmit impulses to the brain for interpretation;

Eustachian tube; link the mouth and middle ear to equalise pressure; between middle and outer ear to prevent damage to delicate eardrum;

Round window; lose excess vibrations; to avoid continuous stimulation;

Semicircular canals; contain receptors for body balance and posture;

External auditory canal cells produce/secrete wax; to trap dust particles/solid/micro-organisms that can damage eardrum;