The Respiratory System — Interactive Diagram
See how air travels from your nose to the tiny air sacs in your lungs, and how oxygen reaches your blood.
TL;DR: See how air travels from your nose to the tiny air sacs in your lungs, and how oxygen reaches your blood.
Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated
The Respiratory System: See how air travels from your nose to the tiny air sacs in your lungs, and how oxygen reaches your blood.
Why it matters: Breathing supplies the oxygen every cell needs to release energy. The path of air and gas exchange in the alveoli are exam essentials.
The Respiratory System — Step by Step
- Air enters through the NOSE, gets warmed and filtered, then goes down the windpipe (TRACHEA).
- The trachea splits into two BRONCHI, one into each lung. These branch into smaller tubes ending in tiny air sacs (ALVEOLI).
- In the alveoli, OXYGEN passes into the blood and CARBON DIOXIDE passes out to be breathed away. This is gas exchange.
Quick Notes — the Exam Crux
- Air enters through the nose (where it is filtered and warmed) → pharynx → larynx → trachea (windpipe).
- The trachea branches into two bronchi, then finer bronchioles, ending in air sacs called alveoli.
- Alveoli have very thin walls and a rich blood supply — O₂ diffuses into the blood and CO₂ diffuses out.
- The diaphragm and rib muscles change the chest volume to draw air in (inhale) and push it out (exhale).
- Oxygen is carried by haemoglobin in red blood cells to every body cell.
- Cellular respiration releases energy: glucose + O₂ → CO₂ + water + energy.
Remember It (Memory Trick)
Air's path: Nose → Trachea → Bronchi → Bronchioles → Alveoli. Gas exchange happens in the alveoli — "Alveoli = Air sacs where air swaps": O₂ in, CO₂ out.
Real-Life Example
Blow onto a cold mirror and it fogs up — you are breathing out water vapour and CO₂ that your cells produced while releasing energy from food.
Test Yourself
Where does the exchange of gases take place in the lungs?
In the alveoli (the tiny air sacs).
Which muscle contracts and flattens when you breathe in?
The diaphragm.
What makes the alveoli so efficient at gas exchange?
Their thin walls, huge surface area and rich blood supply allow rapid diffusion of O₂ and CO₂.
📖 Read the full explanation of The Respiratory System →
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