Question

Give reasons .the lungs always contain a residual volume of air

Answer 1

otherwise lungs would Collado so even if u exhale hard some resedual volume always remsins in lungs so as to prevent the lungs from collasping

Answer 2

Residual volume is the amount of gas remaining in the lungs at the end of a maximal exhalation. The lungs always contain a residual volume of air so that during breathing cycle there is sufficient time for oxygen to be absorbed and for the carbon dioxide to be released

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