Question

Write a note on the human ear.

Answer 1

Human ear:

1. It is the sense organ of the human body.
2. It helps in the identification, amplification, and detection of sound.
3. It also helps in maintaining a sense of balance.

Ear structure:

The human ear is composed of three parts:

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

1. External ear: Further divided into the following parts:

Auricle: Consists of elastic cartilage surrounded by a skin layer.

External auditory meatus:

1. Slightly curved canal, outer part protected by cartilage and inner part protected by bone.
2. Wax glands are present.

Tympanic membrane:

1. Separates the middle ear and the outer ear.
2. Receives sound waves and amplifies them.

2. Middle ear: Comprises of following parts:

Tympanic Cavity:

1. Small air-filled space.
2. Divided by the tympanic membrane (External ear) and bony wall (Inner ear).

Eustachian Tube:

1. Joins nasopharynx to the tympanic cavity.
2. Equalizes both sides of the tympanic membrane to air pressure.

Ear ossicles:

1. Malleus, incus and stapes are ear ossicles of middle ear.
2. Transmitted sound waves from the eardrum to the middle ear.

3. Inner ear: Comprises two parts:

Bony labyrinth:

1. Consist of a vestibule, three semicircular canals, and coiled spiral cochlea
2. It is made of perilymph.

Membranous labyrinth:

1. Includes sensory receptors responsible for balance and hearing.
2. A bony labyrinth surrounds the membranous labyrinth.