
Gas
Inhaled air %
Exhaled air %
Oxygen
21
16
Carbon dioxide
0.03
4.4
Nitrogen
78
78
What has raised the percentage of carbon dioxide in exhaled air?
Important Questions on Respiration - The Energy Producing System
The middle step between the gaseous exchange at lung’s level and tissue level is _____.


Skin: Sweat : Lungs: _____





Neha went to the lakeside for a picnic with her friends. Suddenly they noticed a man drowning in the lake. Everyone was frightened but Neha asked them to stop panicking and take the man out of water. After the man was rescued, he was found unconscious. Neha then suggested that mouth-to-mouth artificial respiration should be given to save the man. One of her friends did as she guided. Finally, the man was saved. He thanked Neha and her friends for their help.
(i) Why is artificial respiration given?
(ii) Can artificial respiration bring back a person to consciousness even after death?



Differentiate between external and internal (or cellular) respiration.

Diaphragm.









