Question

Give Reasons:
1.Rings of cartilage are present in trachea.
2.Lungs always contain residual volume of air.

Answer 1

1) rings of cartilage along the trachea Helps the Oxygen to pass through the wind pipe easily as it doesn't let it to collapse.
2)lungs always contain a residual volume of airas it provides sufficient time for the oxygen and carbon dioxide to be released....

Hope this will be helpful to you dear!

Answer 2

Answer:

1. FROM NOSTRIL, THE AIR PASSES THROUGH THE PHARNYX INTO LUNGS VIA TACHEA. INCOMPLETE C-SHAPED RINGS OF CARTILAGE ARE PRESENT IN THE TRACHEA WHICH ENSURES THAT THE AIR PASSAGE DOES NOT COLLAPSE WHEN THERE IS NO AIR IN IT.

2.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. Residual volume is important because it prevents the lungs from collapsing.