Ear (sense of hearing).

 Now I'm going to tell you about Ear.

The ear is concerned with sense of hearing and equilibrium. It is divided into the three following parts-

1. External ear.
2. Middle ear.
3. Internal ear.

• External ear-It is the only part which lies outside the skull. It contains the following structure.

1. Pinna or curricle-Pinna is a fumed shaped organ mode elastic fibro cartilage. It helps to ccollect the sounds waves.
2. External auditory meatus- which is a small channel lined by skin and wax secreting glands. It conveys the vibration of sound to the tympanic membrane.

• Middle ear- Tympanic cavity it is a small cavity in the temporal bone ,it contains-

1.Tympanic membrane or ear drum which forms the lateral wall.

2.Two foramina in the inner wall called =>fenestra rotundum or round window. or fenestra ovalis or oral window. 

3.Evatachain through which middle ear communicate anteriorly with  Nosapinary nex .