When we breathe, we inhale(take in) and exhale(let out) air. How can we tell? Our chest move up and down. The number of chest movement is the rate of breathing.
As we inhale, the chest rises outwards and upwards causing the chest to expand. The air is taken in through the nose, down the windpipe into the lungs. This air contains more oxygen.
As we exhale, the chest moves in causing the chest to contract. The air inside the lungs then flows out from the lung to the windpipe and then out through the nose.This air contains more carbon dioxide.
Answer the questions.
1. Name P and Q.
i) P: lung ii) Q: windpipe
2. What is P used for?
P is used for breathing.
3. What is Q used for?
Q is used to let the air flows into and out from the lungs.