Class 3 · Environmental Studies
Our body
📘 Chapter notes
The key ideas of this chapter, answered through the six guiding questions. Read them with your textbook.
1What am I looking at?
Answer: The outside and inside parts of our body and keeping it healthy.
2What are its main parts or ideas?
Answer: External parts; internal organs: brain, heart, lungs, stomach; bones and muscles.
3How does it work?
Answer: The heart pumps blood, the lungs help us breathe, the stomach digests food, bones support us.
4Why is it important?
Answer: Healthy habits — exercise, sleep, clean food — keep the body working well.
5What happens if something changes?
Answer: Breathing gets faster when we run because the body needs more air.
6What should I remember for the exam?
Answer: Name organs and their jobs and list healthy habits.
📗 Full lesson: Human body, senses and hygiene
This topic comes from GayaGnan's India-wide K–12 catalog. It is not copied from, or an official chapter of, any board's textbook: check your board's syllabus for the exact chapter and depth. Open as its own page →
🧊 3D / visual
🧊 3D
ℹ️ Organs simplified and coloured for clarity.
VIS-015 · Digestive, respiratory, circulatory, nervous systems — Layer visibility; trace process; organ detail
🎯 Learning outcomes
- Name major internal organs and organ systems (digestive, breathing, circulation, skeleton, muscles)
- Explain how sense organs work with the brain
- Explain how germs spread and how hygiene, vaccination and clean surroundings prevent disease
Before you start: External body parts and the five senses.
📖 Explanation
Inside the body, organs work in teams called systems. The digestive system (mouth, food pipe, stomach, intestines) breaks food down. The lungs take in oxygen and give out carbon dioxide. The heart pumps blood through blood vessels to every part. The skeleton supports and protects, and muscles move bones.
Sense organs send messages along nerves to the brain, which decides what to do: when you touch something hot, the message travels to the brain or spinal cord and you pull your hand away quickly.
Germs spread through dirty water, unwashed hands, coughs and sneezes, flies and mosquitoes. Washing hands, covering coughs, safe water, clean toilets and vaccines prevent many diseases. Stagnant water lets mosquitoes breed, spreading malaria and dengue.
India's Pulse Polio campaign gave polio drops to crores of children, and India was declared polio-free in 2014.
✗ The heart is on the far left of the chest
✓ The heart sits roughly in the middle of the chest, tilted slightly to the left, between the lungs.
🧪 Try this activity
Count your pulse at the wrist for one minute while sitting, then after skipping for one minute. Explain why it is faster after exercise.
✍️ Question bank with answers
Tap an option to check multiple-choice answers. Open “Answer” or “Marking points” for the others.
-
Which organ pumps blood?
Answer
B. heart
The heart pumps blood through the body.
-
Mosquitoes breed in
Answer
B. stagnant water
Still water in pots, tyres and coolers lets mosquitoes lay eggs.
-
Which system breaks down food?
Answer
A. digestive
The digestive system digests food.
-
Which organ controls the whole body?
Answer
the brain
-
Name a disease spread by mosquitoes.
Answer
malaria or dengue
-
Why should we cover our mouth while coughing or sneezing?
Marking points
- Germs spread through tiny droplets in the air
- Covering stops them reaching others
-
Describe the journey of food from mouth to intestines.
Marking points
- Teeth chew and saliva mixes in the mouth
- Food pipe carries food to the stomach
- Stomach churns and digests
- Small intestine absorbs digested food; waste goes on
-
Water collects in an old tyre near your home. What should be done and why?
Answer
- Empty it or cover it
- Stops mosquitoes breeding and spreading dengue or malaria
-
Draw an outline of the body and mark the heart, lungs, stomach and brain.
Answer
- Brain in the head
- Lungs on both sides of the chest
- Heart between the lungs
- Stomach in the upper abdomen
🎲 Practice more
A new set of questions every time you press the button. Tap an option to check it and see why. Maths, science, computer and commerce sets get fresh numbers and pictures on every try.
Turn on JavaScript to get practice sets.
🎯 Learning objective: Locate the main organs of the human body and group them into organ systems.
💬 Questions and answers
1What am I looking at?
Answer: A see-through human body showing the major organs and bones in their real positions.
2What are its parts? (click a part to identify it)
Answer: Brain and spinal cord (nervous), windpipe, lungs and diaphragm (respiratory), heart and blood vessels (circulatory), food pipe, stomach, liver, pancreas and intestines (digestive), kidneys and bladder (excretory), glands (endocrine) and the skeleton.
3How does it work?
Answer: Organs work in teams called systems. Food is digested and absorbed, the lungs take in oxygen, the heart pumps blood that carries both to every cell, the kidneys remove waste, and the brain controls everything.
4Why is it important?
Answer: Knowing where organs are and what they do helps you understand health, illness, first aid and the human-biology chapters of Classes 5 to 12.
5What happens if I change something? (use the sliders)
Answer: Switch systems on and off to see one team at a time, take the body apart to separate organs, and make the skin clearer or more solid.
6What should I remember for the exam?
Answer: Organ system → organs → function. Example: digestive system = mouth, oesophagus, stomach, small and large intestine, with liver and pancreas.