Compliance and Air Way Resistance

Compliance and Air Way Resistance

Compliance is a measure of distensibility. Lung compliance is defined as the change in volume per unit change in pressure. Airway resistance denotes the measure of obstruction to the flow of gas in the air passages. Flow of gas in a tube depends on a number of factors. Anything that reduces the size of the air passage will interfere with flow and therefore increase the airway resistance. Most of the resistance to air flow is in bronchi greater than 2 mm in diameter. Airway resistance is increased in asthma, emphysema, pulmonary congestion etc. In these conditions the work of breathing is increased.