Your body is like a wonderful machine. On the outside, you can see your skin, hands, legs, and face. But inside, there are many important parts called organs that work together to keep you alive and healthy. Just like a car needs an engine, fuel, and wheels to run, your body needs the brain to think, the heart to pump blood, the lungs to breathe, and the stomach to digest food.
| Organ | Location | Main Function |
|---|---|---|
| Brain | Inside the skull (head) | Controls thinking, memory, feelings, and all body actions |
| Heart | In the chest, slightly to the left | Pumps blood to all parts of the body |
| Lungs | In the chest, on both sides of the heart | Help us breathe -- take in oxygen and release carbon dioxide |
| Stomach | In the upper part of the abdomen | Digests the food we eat and breaks it into smaller parts |
When Ananya runs during her PT class, her brain tells her legs to move. Her heart beats faster to pump more blood. Her lungs breathe in more air to supply oxygen. Later, the food she ate at lunch gives her the energy -- her stomach had already digested it.
Think: Place your hand on the left side of your chest. Can you feel your heart beating? It beats about 70-100 times every minute.
The skeletal system is the framework of bones inside your body. An adult human body has 206 bones. Bones perform three important jobs:
The place where two bones meet is called a joint. Your elbow, knee, and shoulder are examples of joints.
Think: Touch the top of your head, your elbow, and your knee. You can feel the hard bones under the skin.
Your body has more than 600 muscles. Muscles are attached to bones and help the body move. When you lift your school bag, the muscles in your arm pull the bones to make your arm bend.
Some muscles work without you thinking about them. For example, the heart is a muscle that keeps pumping blood day and night. The muscles in your stomach help digest food automatically.
When Ravi kicks a football during recess, the muscles in his leg contract (become shorter and tighter) to push his leg forward. When he smiles at his friends, the muscles in his face move to form the smile.
| Word | Meaning |
|---|---|
| Organ | A part of the body that does a special job (e.g., heart, brain) |
| Skeleton | The framework of all the bones in the body |
| Joint | The place where two bones meet, allowing movement |
| Muscle | A body part that contracts and relaxes to produce movement |
| Digest | To break down food into smaller parts the body can use |
To keep your body strong and healthy, you need regular exercise and enough sleep.
Think: What happens when you do not sleep well? You feel tired, cannot concentrate in class, and may fall sick more easily.
A. Fill in the Blanks
B. Match the Organ with Its Function
| Organ | Function |
|---|---|
| Brain | |
| Heart | |
| Lungs | |
| Stomach |
(Functions: Pumps blood / Digests food / Controls thinking / Helps us breathe)
C. Multiple Choice Questions
D. Short Answer Questions
For one day, observe how your body works. Fill in the table below.
| Activity | Which Organ / Body Part Helped? |
|---|---|
| Eating breakfast | |
| Running to school | |
| Solving a maths problem | |
| Breathing during yoga | |
| Lifting your school bag |