Ear

The ear is an organ used for hearing and balance. Most humans have two ears, one on each side of the head. The main task of the ear is to collect sounds from the environment and change them into signals the brain can understand. The ear also helps the body know its position and movement. This ability is called balance. Many animals have ears, but their shape and position can be different from human ears.

The ear has three main parts. These parts are called the outer ear, middle ear, and inner ear. Each part has a different job. The outer ear is the part that can be seen on the outside of the head. It includes the ear flap, also called the pinna. The ear flap collects sound waves and directs them into the ear canal. The ear canal is a narrow passage that leads sound inward.

At the end of the ear canal is the eardrum. The eardrum is a thin membrane, which means a thin layer of tissue. When sound waves hit the eardrum, it vibrates. These vibrations move into the middle ear. The middle ear contains three very small bones. They are called the hammer, anvil, and stirrup. These names come from their shapes. The bones make the vibrations stronger and pass them along.

The vibrations then move into the inner ear. The inner ear contains a spiral-shaped part called the cochlea. The cochlea is filled with fluid and tiny hair-like cells. When vibrations enter the cochlea, the fluid moves. This movement bends the hair cells. The hair cells change the movement into electrical signals. These signals travel through the auditory nerve to the brain. The brain understands these signals as sound, such as voices, music, or noise.

The inner ear also helps with balance. It contains structures called semicircular canals. These canals are filled with fluid and help detect movement of the head. When the head moves, the fluid shifts. This sends signals to the brain about direction and speed. Balance allows people to stand, walk, and move without falling. Hearing and balance work together, but they are controlled by different parts of the inner ear.

Ears need protection because they are sensitive. Earwax helps protect the ear canal by trapping dust and small particles. The shape of the ear also helps keep objects out. Loud sounds can damage the ear, especially the hair cells in the cochlea. Once damaged, these cells usually do not heal. Even though ears can look simple on the outside, they are complex organs that play an important role in daily life.