The Excretory System

🧠 BASIC SCIENCE E-NOTE

Class: Primary 5

Subject: Basic Science

Topic: The Excretory System

Duration: 40 minutes

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🌿 Meaning of Excretory System

Every day, our body produces waste — things it no longer needs.
These wastes come from the food we eat, the air we breathe, and the work our body does.

👉 The excretory system is the body system that removes waste and harmful substances from the body.
Without it, waste would build up and make us sick!

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💪 Organs Involved in the Excretory System

There are special organs that help our body remove different kinds of waste. Let’s learn about them:

1. 🧍‍♀️ Kidneys

   • We have two kidneys.

   • They remove liquid waste from the blood in the form of urine.

   • The urine passes into the bladder, where it is stored until we urinate.

2. 💨 Lungs

   • The lungs remove carbon dioxide (a gas) when we breathe out.

   • Try this: Breathe out slowly — that’s waste gas leaving your body!

3. 💦 Skin

   • The skin removes sweat, which contains water and salt.

   • That’s why your skin feels wet and salty when you sweat.

4. 💧 Bladder

   • The bladder stores urine until we go to the toilet to release it.

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🧩 Quick Summary

Organ	Waste Removed	Form of Waste
Kidneys	Urea, water	Urine
Lungs	Carbon dioxide	Gas
Skin	Water, salt	Sweat
Bladder	Stores urine	Liquid

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🧍‍♂️ Why Excretion Is Important

• It keeps the body clean inside.

• It prevents sickness from harmful waste.

• It helps the body work properly.

If waste stays inside the body, a person can fall sick or even die. So, excretion is very important!

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✍️ Class Activity

1. Mention three organs of the excretory system.

2. Draw and label the human excretory system.

3. Discuss what might happen if waste is not removed from the body.

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📚 Evaluation Questions

1. What is the excretory system?

2. Mention two examples of waste products removed from the body.

3. Which organ removes carbon dioxide?

4. What is the function of the kidneys?

5. Name one way your skin helps in excretion.