Ear anatomy
 

[B]EAR:[/B]
The ear is an important sensing organ, it consist of 3 important parts, mainly the......
1.[B]External Ear[/B]
2.[B]Middle Ear[/B]
[B]3.Internal Ear[/B]

[B]WORKING OF EAR:[/B]
Sound is collected by the pinna (the visible part of the ear) and directed through the outer ear canal. The sound makes the eardrum vibrate, which in turn causes a series of three tiny bones (the hammer, the anvil, and the stirrup) in the middle ear to vibrate. The vibration is transferred to the snail-shaped cochlea in the inner ear; the cochlea is lined with sensitive hairs which trigger the generation of nerve signals that are sent to the brain.
[B]On average, people can hear sounds in the frequencies between 30 to 30,000 Hertz. [/B]

[B]PARTS OF EAR:[/B]

[B]anvil [/B]- (also called the incus) a tiny bone that passes vibrations from the hammer to the stirrup.

[B]cochlea [/B]- a spiral-shaped, fluid-filled inner ear structure; it is lined with cilia (tiny hairs) that move when vibrated and cause a nerve impulse to form.

[B]eardrum -[/B] (also called the tympanic membrane) a thin membrane that vibrates when sound waves reach it.

[B]Eustachian tube [/B]- a tube that connects the middle ear to the back of the nose; it equalizes the pressure between the middle ear and the air outside. When you "pop" your ears as you change altitude (going up a mountain or in an airplane), you are equalizing the air pressure in your middle ear.

[B]hammer -[/B] (also called the malleus) a tiny bone that passes vibrations from the eardrum to the anvil.

[B]nerves -[/B] these carry electro-chemical signals from the inner ear (the cochlea) to the brain.

[B]outer ear canal [/B]- the tube through which sound travels to the eardrum.

[B]pinna - [/B](also called the auricle) the visible part of the outer ear. It collects sound and directs it into the outer ear canal.

[B]semicircular canals -[/B] three loops of fluid-filled tubes that are attached to the cochlea in the inner ear. They help us maintain our sense of balance.

[B]stirrup - [/B](also called the stapes) a tiny, U-shaped bone that passes vibrations from the stirrup to the cochlea. This is the smallest bone in the human body (it is 0.25 to 0.33 cm long).