ABSTRACT
The primary function of the pulmonary system is to enable gaseous exchange between the blood and the atmosphere, where oxygen diffuses to the blood and carbon dioxide diffuses from the blood. Diseases that disturb gaseous exchange affect oxygen saturation in blood and tissues and contribute to acid-base disturbances. Since the lungs and airways are in direct contact with the atmosphere, they are exposed to a number of harmful agents which may cause disease. The most frequent diseases of the pulmonary system are acute infections, allergies and inflammation, which contribute to obstructive lung diseases which may lead to lower alveolor ventilation and reduced gas exchange.
