Gas exchange involves the movement of oxygen (O₂) from the alveolus (gas exchange units in the lung) to the blood (i.e., diffusion across the alveolar capillary membrane) and movement of carbon dioxide (CO₂) from the blood into the alveolus for subsequent removal. Gas exchange in the lungs is referred to as respiration, whereas the movement of gas in and out of the lung is ventilation.

Subtopic(s):

• Arterial Blood Gas (ABG) Analysis
• Alveolar-Arterial Gradient (A-a Gradient); Arterial/Alveolar Oxygen Ratio (a/A Ratio)
• Partial Pressure of Carbon Dioxide (Pco(2))
• Oxygen Saturation (So(2))
• Arterial Oxygen Content (Cao(2)); Mixed Venous Oxygen Content (Cvo(2))
• Partial Pressure of Oxygen (Po(2))
• Total Carbon Dioxide Content (Tco(2))
• Blood pH
• Base Excess or Deficit
• Lactic Acid (Lactate)