Question

Draw a well labelled diagram of an ear.

Answer 1

Hint: Ear is a human organ which helps in hearing.
 It lies on the external surface.
In mammals it is also believed to maintain the balance.
It consists of pinna and an ear canal.

Complete answer:
Ear is an organ for hearing.
The ear develops from the first pharyngeal arch.
These are derived from the ectoderm layer.
It has three parts—outer ear, middle ear and inner ear.
The outer part of the ear includes the pinna and ear canal.
The outer part of the ear is the only visible part.
The middle part of the ear consists of a tympanic cavity and three ossicles.
The inner part has multiple tiny parts which are the key to all the senses.
These include semicircular canals (for balance on moving), utricle and saccule (for balance on rest), cochlea (for hearing).
Both the ears are symmetrical.
The outer ear, the pinna has an outer curve called helix and the inner rim called antihelix.
The ear canal is 1 inch long.
In the beginning the canal is surrounded by cartilage and at the end it has bone.
The bone here involved is a tympanic part of the temporal bone.
The skin around this canal contains sebaceous glands which produce ear wax.
Middle ear consists of an air filled cavity known as a tympanic cavity.
It includes three ossicles i.e malleus, incus and stapes.
The stapes is known as the smallest bone in the body.
These transmit sound from the outer part to the inner part of the ear.
Inner ear receives vibrations from the middle ear (incus).

Note: The ear develops from the first pharyngeal arch.
These are derived from the ectoderm layer.
The stapes is known as the smallest bone in the body.
The ear canal is 1 inch long.