The Lungs in Space: A Review of Current Knowledge and Methodologies.

Space travel presents multiple risks to astronauts such as launch, radiation, spacewalks or extravehicular activities, and microgravity. The lungs are composed of a combination of air, blood, and tissue, making it a complex organ system with interactions between the external and internal environment. Gravity strongly influences the structure of the lung which results in heterogeneity of ventilation and perfusion that becomes uniform in microgravity as shown during parabolic flights, Spacelab, and Skylab experiments.