Читать книгу Respiratory Medicine - Stephen J. Bourke - Страница 37

 The essential function of the lungs is the exchange of oxygen and carbon dioxide between the blood and the atmosphere.

 Ventilation is the process of moving air in and out of the lungs, and it depends on the tidal volume, respiratory rate, resistance of the airways and compliance of the lungs. A fall in ventilation leads to a rise in PCO2 and a fall in PO2: type 2 respiratory failure.

 Derangement in the matching of ventilation and perfusion in the lungs (which may be caused by any disease intrinsic to the lung or its vasculature) leads to a fall in PO2: type 1 respiratory failure.

 The respiratory centre in the brain stem is responsible for the control of breathing. pH and PCO2 are the primary stimuli to ventilation. Hypoxia only acts as a stimulant when PO2 < about 8 kPa.