Five Senses

FIVE SENSES

Your eyes and your ears give you the ability to see and hear.

Let's see how they work.

Seeing, a matter of Light!

You can see objects because light off them. Check how light enters your eyes and is transformed into information!

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​Seeing and hearing

1. First, light passes through a transparent covering called the cornea, which protects the eye.
2. Then light must travel through your pupil. The pupil gets bigger and smaller because the colored part of your eye, called the iris, opens and closes to control the amount of light that enters your eye.
3. Next,  the light passes through the lens, which focuses the light from the object on the retina.  When an image reaches your retina, it is actually  upside down.
4. The retina is a thin piece of tissue covered with very sensitive cells. These cells transform the light into electric impulses, which travel to the brain through the optic nerve.
5. Finally, the brain takes the message and reconstructs the image to a right side up picture, just like the one you are seeing now!

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Seeing

Multiple Choice

What is the main function of the cornea in the eye?

• To control the amount of light that enters the eye.

• To protect the eye and allow light to pass through.

• To transform light into electric impulses.

Multiple Choice

What happens to the image when it first reaches the retina?

• It appears upside down.

• It is already in the correct position.

• It is converted into sound.

When an object vibrates, it makes the air around it vibrate too and this vibration makes sound. Sounds travel through the air by vibrating the air particles and entering your ears. 

The pinna or outer ear is the fleshy part of your ear that is on each side of your head. Vibrations enter the ear through the pinna, travel up the ear canal, and vibrate a thin piece of skin called the eardrum.

The eardrum make three small bones, called the anvil, the stirrup, and the hammer, vibrate. These small bones make the cochlea vibrate.

The cochlea converts these vibrations into electrical impulses which travel to the brain through the auditory nerve.

The brain interprets the electrical impulses as sounds.

Hearing

Multiple Choice

What is the function of the cochlea in the ear?

• To vibrate the eardrum.

• To convert vibrations into electrical impulses.

• To make the pinna vibrate.

Multiple Choice

Which part of the ear is responsible for receiving the initial vibrations from the air?

• The cochlea

• The eardrum

• The pinna

Air enters your body through two holes in your nose called nostrils. Your nose is the organ you use to smell with. When you breathe in, the odor particles that are in the air are perceived by the smell receptor inside your nose. When the particles touch the receptors, they send the messages to the brain through the olfactory nerve.

Smell

Multiple Choice

What is the main function of the nose?

• To help you hear.

• To help you smell.

• To help you see.

Multiple Choice

How do odor particles send messages to the brain?

• By vibrating the eardrum.

• By passing through the nostrils directly to the brain.

• By touching smell receptors and traveling through the olfactory nerve.

Different types of taste buds are located in different places on your tongue. Observe the illustration and draw lines to match the food with the place on your tongue that can identify the flavor. Your toungue and the roof of your mouth are covered with tiny taste buds which allow you to experience sour, sweet, salty, and bitter tastes. When you eat, the nerves in your taste buds send messages to your brain, which identifies the information.

Tastes

Multiple Choice

Where are taste buds located?

• Only on the sides of your tongue.

• Only on the roof of your mouth.

• On your tongue and the roof of your mouth.

Multiple Choice

What do taste buds do when you eat?

• They change the flavor of the food.

• They send messages to your brain to identify the taste.

• They make the food salty.

Your skin is the organ that you use to touch and feel things. The skin has three layers, epidermis, dermis and hypodermis. The epidermis is the external layer of the skin, which protects your body from bacteria and viruses. Below the epidermis is the dermis. Which contains sweat glands, the glands, the glands that produce sweat. Sweat leaves your skin through small holes called pores. The hypodermis stores fat as a source of energy and creates a fat layer that keeps your body warm. These are several types of nerves inside your skin; each nerve senses something different. For example, you have pressure sensors,heat sensors, cold sensors and even pain sensor. These sensors send information to your brain about the things you touch.

Touching

Multiple Choice

Which layer of the skin protects your body from bacteria and viruses?

• Dermis

• Epidermis

• Hypodermis

Multiple Choice

What is the function of the hypodermis?

• To produce sweat.

• To store fat and keep your body warm.

• To sense pressure and pain.