Your eyes help you see. Light goes into your eye. It goes through an opening called the pupil. The cornea is a dome-shaped clear layer at the front of the eye. It bends light. At the very back of the eye is the retina. It is a light-sensitive layer.

The pinna is the part of the ear you can see on the side of your head. Sound waves go into your ears. They make your eardrums vibrate. Three tiny bones in the middle ear pass this on. The cochlea is a snail-shaped part of the inner ear. It turns vibrations into nerve signals.

Your nose lets you smell. Smell helps you taste. Without smell, foods taste bland. You use your tongue to taste. People are born with about 10,000 taste buds. You may have heard there are only four tastes. In fact, taste buds can detect sweet, sour, bitter, salty and umami (savory) flavors.

The epidermis is the top layer of your skin. Your skin has nerve endings. They let you feel hot, cold and touch. You might think every part of your skin feels touch the same. In fact, fingers and lips have more touch receptors than your back. So they feel more.

Braille is a way of reading with the fingers, using raised dots. American Sign Language (ASL) is the primary language of many North Americans. They are deaf or hard of hearing. It is expressed by movements of the hands and face.

Your senses send messages to your brain. You may think your eyes alone make the picture you see. In fact, the optic nerve carries signals from the eye to the brain. The auditory nerve carries signals from the ear to the brain.

Words to know

• cornea: clear front layer
• cochlea: snail-shaped ear part
• epidermis: top skin layer
• braille: raised dots
• retina: back of eye