What is dead space of lungs?

There are two types of dead space-

1.       Anatomical

2.       Physiological

Anatomical dead space is the area included in the first 16 generation of the bronchial tree. Its by virtue of the normal anatomical structure that this area is unable to take part of in the exchange of gases

The physiological dead space is when there is decreased blood supply to a particular part of the lung, but the air entering the same part is normal. Hence there is no exchange of gases. In other words there is an increase in V/Q ratio.

Extra-

There is an entity called shunt formation in lungs..its when the blood supply to an area of lung is normal but there as a decrease in the ventilation of this area. Hence the blood remains deoxygenated and mixes with oxygenated blood from the normally ventilated areas.