The 5 Senses

The 5 Senses: Part 1

Discuss the text and solve the questions

Sight: What Are the Eyes and How Do They Work?

Which part of your body lets you read the back of a cereal box, check out a rainbow, and see a football heading your way? Which part lets you cry when you're sad and makes tears to protect itself? Which part has muscles that adjust to let you focus on things that are close up or far away? If you guessed the eye, you're right!

Your eyes are at work from the moment you wake up to the moment you close them to go to sleep. They take in tons of information about the world around you — shapes, colors, movements, and more. Then they send the information to your brain for processing so the brain knows what's going on outside of your body.

What Are the Eyes and How Do They Work?

After light enters the pupil, it hits the lens. The lens sits behind the iris and is clear and colorless. The lens' job is to focus light rays on the back of the eyeball — a part called the retina. Your retina is in the very back of the eye. It holds millions of cells that are sensitive to light. The retina takes the light the eye receives and changes it into nerve signals. Then, the optic nerve carries those messages from the eye to the brain so the brain can understand what the eye is seeing.

Multiple Choice

This part of the eye carries the message from your eye to the part of your brain that controls vision. 

• cornea
• lens
• optic nerve
• retina

Multiple Choice

Pupil

• Focuses light
• Clear tissue that covers the front of the eye
• Opening through which light enters the eye
• Layer of receptor cells

Hearing: What Are Ears and What Do They Do?

The ear is made up of three different sections that work together to collect sounds and send them to the brain: the outer ear, the middle ear, and the inner ear. The outer ear is the part we can see.  Its main job is to gather sounds and funnel them to the ear canal, which is the pathway that leads to the middle ear.

Hearing: What Are Ears and What Do They Do?

The middle ear is an air-filled cavity that turns sound waves into vibrations and delivers them to the inner ear. The middle ear is separated from the outer ear by the eardrum, a thin piece of tissue stretched tight across the ear canal. Sounds hit the eardrum, making it move. This movement leads to vibrations of three very small bones in the middle ear known as the ossicles.

Hearing: What Are Ears and What Do They Do?

The vibrations from the middle ear change into nerve signals in the inner ear. The inner ear includes the cochlea. The snail-shaped cochlea changes the vibrations from the middle ear into nerve signals. These signals travel to the brain along the cochlear nerve, also known as the auditory nerve.

Multiple Choice

The cochlea is filled with fluid. The fluid move tiny hairs. What happens next?

• sound stops here

• messages are sent to the brain

Multiple Choice

What does the ear drum do as it receives sound?

• it starts to vibrate

• it does nothing

• it bursts

Touch: How you skin works

Without skin, people's muscles, bones, and organs would be hanging out all over the place. Skin holds everything together. It also:

protects our bodies helps keep our bodies at just the right temperature allows us to have the sense of touch

Touch: How you skin works

The nerve endings in your skin tell you how things feel when you touch them. They work with your brain and nervous system, so that your brain gets the message about what you're touching. Is it the soft fur of a cat or the rough surface of your skateboard? Sometimes what you feel is dangerous, so the nerve endings work with your muscles to keep you from getting hurt. If you touch something hot, the nerve endings respond right away: "Ouch! That's hot!" The nerves quickly send this message to the brain or spinal cord, which then immediately commands the muscles to take your hand away. This all happens in a split second, without you ever thinking about it.

Multiple Choice

True or False: The brain is the largest organ in the body.

• True

• False

Multiple Choice

Skin is a sense organ.

• True

• False