Define the following terms?
(a) Tidalvolume
(b) Residualvolume
(c) Asthma

Explanation

(A) Tidal volume: It is the volume of air inspired or expired during normal respiration and is about 500 ml.
(B) Residual volume: It is the volume of air which remains in the limgs even after foeved expiration and is about 1100 to 1200 ml.
(C) Asthma : It is charactererised by bronchiospasm and narrowing of bronchi and bronchioles which cause difficulty in breathing and wheezing.