QS Study

Pulmonary Ventilation is the inflow and outflow of air between the atmosphere and the lung per minute. This system, also known as the ventilation system, meets the body’s needs for gas exchange at the lungs and at the tissues.

The primary function of pulmonary ventilation is to make oxygen available to the blood, which is transported by the cardiovascular system throughout the body to all the cells. When we expand the lungs to inhale, we increase internal volume and reduce internal pressure. The exchange of oxygen and carbon dioxide at the cellular level is necessary to produce energy for muscle contraction while regulating the internal environment of the tissues. Muscular breathing movements and recoil of elastic tissues create the changes in pressure that result in ventilation.

Fig: Pulmonary Ventilation – inflow and outflow of air

Pulmonary ventilation involves three different pressures:

  • Atmospheric pressure
  • Intraalveolar (intrapulmonary) pressure
  • Intrapleural pressure

Atmospheric pressure is the pressure of the air outside the body. Intraalveolar pressure is the pressure inside the alveoli of the lungs. Intrapleural pressure is the pressure within the pleural cavity. These three pressures are responsible for pulmonary ventilation.