The entire process of exchanging gases between the atmosphere and body cells is called respiration. Therefore the primary function of the respiratory system is to supply the body with oxygen and remove carbon dioxide.
In respiration several distinct processes can be distinguished:
- Ventilation – movement of air into and out of the lungs
- External respiration – gas exchange between blood and the air-filled chambers of the lungs
- Distribution – transport of gases between the lungs and the rest of the body tissues
- Internal respiration – gas exchange between systemic blood and the tissue cells
- Cellular respiration – the mitochondrial process in which oxygen is utilized during ATP synthesis
In asthma the process of ventilation is impaired due to changes in airway calibres.
Klinke R, Silbernagel S. Lehrbuch der Physiologie. 2001. Thieme: Stuttgart
Shier D, Butler J, Lewis R. Hole’s human anatomy and physiology. 2004. McGraw Hill: New York