Question

With regard to the respiratory system and the process of respiration in man, answer the following question: 

What is meant by :

1. Residual air and
2. Dead air space

Answer 1

1. Residual air: Some air is always left in the lungs even after forcibly breathing out. This is the leftover or residual air. This volume is 1500 mL.

2. Dead air space: Some tidal air is left in the respiratory passages such as the trachea and bronchi, where no diffusion of gases can occur. This volume is called dead air space. It is 150 mL.