Читать книгу Respiratory Medicine - Stephen J. Bourke - Страница 15

The core business of the lungs is to bring oxygen into the body and to take carbon dioxide out. The deceptively simple act of ‘breathing’ comprises two quite distinct processes.

1 Ventilation. The movement of air in and out of the lungs (between the outside world and the alveoli).

2 Gas exchange. The exchange of oxygen and carbon dioxide between the airspace of the alveoli and the blood.

Ventilation continues throughout life, largely unconsciously, coordinated by a centre in the brain stem. The factors that regulate the process, ‘the control of breathing’, will also be considered here. Gas exchange happens automatically (by diffusion) if blood and inspired air are brought into close proximity.