Question

give reasons of the following

Lungs always contain residual volume

Nostrils are kined with mucus

Answer 1

• Lungs always contain residual volume of air so there is sufficient time for oxygen to be absorbed and carbon dioxide to be released.
• Also it helps air passage not to collapse.
• Nostril is lined with mucus as it helps in filtering the air.
• Also it does not allow harmful foreign particle to inside your nostril.