PATHOLOGY

Detailed explanation-1: -Inhaled air contains approx 21%oxygen, 0.04% carbon dioxide and 79%nitrogen while exhaled air contains approx 16% oxygen, 4% carbon dioxide and also 79% nitrogen.

Detailed explanation-2: -In turn, exhaled air contains: nitrogen – 78% oxygen – 17% carbon dioxide – 4% other gases – 1%.

Detailed explanation-3: -’ Nitrogen makes up 78 per cent of the air we breathe, and it’s thought that most of it was initially trapped in the chunks of primordial rubble that formed the Earth. When they smashed together, they coalesced and their nitrogen content has been seeping out along the molten cracks in the planet’s crust ever since.