Page 137 - Primary Six Notes

The human ear is a sensory organ used for hearing sound.

The ear also helps in balancing the body in the right position.

The ear is divided into three:

1. Outer ear

2. Middle ear

3. Inner ear

The outer ear.

 The outer ear is made up of the pinna and auditory canal.

The pinna helps to trap or collect sound waves and direct

them to the auditory canal.

 In the outer ear, there is hair to trap dust and other foreign

bodies before damaging the ear drum.

The middle ear.

 This consists of the three bones called the ossicles. i.e. malle-

us (hammer), incus (anvil) and stapes (stirrup).

 The ossicles amplify and transmit the vibrations produced

by the ear drum across the middle ear to the inner ear.

 It also contains the Eustachian tube to balance air pressure

between the ear and atmospheric pressure.

The inner ear.

 This consists of the cochlea, semi-circular canal and the au-

ditory nerves.