10.20 Hearing and Balance

10.20.2 Describe the basic anatomy (structure) of the ear.

The ear is composed of three parts:

• the outer ear,
• the middle ear, and
• the inner ear.

The outer ear consists of the pinna and the ear canal, which collect and direct sound waves to the eardrum.

The middle ear is separated from the outer ear by the eardrum and contains three small bones called the ossicles (the malleus, incus, and stapes) that transmit sound vibrations to the inner ear.

The inner ear contains the cochlea, which is responsible for converting sound vibrations into electrical signals that are sent to the brain.

The inner ear also contains the vestibular system, which is responsible for balance and spatial orientation.

10.20.4 Describe the physiology (function) of the ear.

The ear’s primary function is to detect sound waves, convert them into electrical signals, and transmit those signals to the brain for interpretation. It also plays a role in balance.

The ear is divided into three main parts:

• Outer ear: Collects sound waves and channels them down the ear canal to the eardrum.

• Middle ear: The eardrum vibrates with sound waves, and these vibrations are transmitted and amplified by three tiny bones (ossicles: malleus, incus, stapes). The Eustachian tube helps equalise air pressure.