Question

What is residual volume of air? Why do trachea not collapse even there

is no air in it?​

Answer 1

Answer:

Residual volume (RV) is the volume of airremaining in the lungs after maximum forceful expiration. In other words, it is thevolume of air that cannot be expelled, thus causing the alveoli to remain open at all times. The residual volume remains unchanged regardless of the lung volumeat which expiration was started.6 days ago

In trachea , there are C shaped rings of cartilage which helps to hold them evenwhen the air is less in it . Hence they do not collapse.