My Body and My Five Senses

1Your body has three main parts

Stand up and look down at yourself. Your whole body is built from three big pieces:

• Your head — it holds your eyes, ears, nose, mouth and the brain inside.
• Your trunk — the long middle part: your chest, your tummy and your back. Your neck joins it to your head.
• Your limbs — your two arms and your two legs. Limbs are the parts that stick out and move you about.

Your arms bend at the elbow and end in hands with fingers. Your legs bend at the knee and end in feet with toes.

2The parts you cannot see

Press your hand gently on the left side of your chest. Can you feel a soft knocking? Bup-bup… bup-bup… That is your heart. It is a muscle about the size of your own fist, and it never stops. It pushes blood along tiny roads called blood vessels so that every part of you gets food and air.

Now take a big breath in. Your chest rises. That is because your two lungs are filling up with air, like two soft bags. Your lungs take the air your body needs and push out the air it does not want.

Inside your head is your brain. The brain is the boss. When your eyes see the moto, they send the news to the brain. The brain decides “move!” and tells your legs to step aside — all in less than one second.

3Bones and muscles

Feel your arm. It is soft on the outside and hard deep inside. The hard part is bone. All your bones together are called your skeleton. Your skeleton holds you up, so you do not flop like a piece of cloth.

Bones also work like a helmet or a cage:

• The bones of your head, called the skull, are a hard case around your brain.
• The curved bones around your chest, called the ribs, are a cage around your heart and lungs.

Muscles are the soft parts that pull on your bones and make them move. Bend your elbow and squeeze your upper arm — you can feel the muscle go tight. No muscle, no movement.

4Your five senses

A sense is a way your body finds out what is happening around it. Every sense uses a special body part called a sense organ. You have five.

Notice that the skin is a sense organ too — and it is your biggest one, because it covers all of you.

Worked example: which sense told you?

Keza is doing her homework in the sitting room. The kitchen door is shut. Suddenly she says, “Mama is roasting maize!” Which sense told her?

Step 1 — What could not have told her? The door is shut, so her eyes cannot see the maize. She has not put anything in her mouth, so her tongue has not tasted it. She has not touched anything hot, so it is not her skin.

Step 2 — What is left? Only her ears and her nose. Could her ears do it? Crackling on a fire could be many things — it does not say “maize”.

Step 3 — Answer. The smell of roasting maize travelled through the air, under the door, and into her nose. The sense is smell and the sense organ is her nose.

Do you see the trick? To find the right sense, first cross out the ones that could not possibly work.

5Senses that help each other

When Keza has a heavy cold and her nose is blocked, even her favourite food tastes boring. That is because smell helps taste. Your senses are a team, not five strangers.

Try it yourself

Answer each one in your head or in your book first, then tap Show answer to check.

1. Which bones protect your heart and your lungs?
2. Mugisha is blindfolded in a game. His friend puts something in his hands. He says, “It is round, heavy and bumpy — it is an orange!” Which sense did he use?
3. Which body part is the boss that tells your legs to move?
4. Name the sense organ for taste, and one thing it can tell you.
5. Umutoni's arm is soft on the outside but hard deep inside. What is the hard part?

Answers

1. The ribs. They curve round your chest like a cage. (The skull protects the brain — that is a different job.)
2. Touch, using the skin of his hands. His eyes are covered, so sight cannot help him. Touch tells him the shape, the weight and the bumpy skin.
3. The brain, inside your skull. It gets the news from your eyes and ears and then gives the orders.
4. The tongue. It can tell you if food is sweet, salty, sour or bitter.
5. Bone. All your bones together make your skeleton, which holds your body up.