What is the thickness of a typical respiratory membrane?

The thickness of a typical respiratory membrane is approximately 0.5 micrometers (μm). This membrane, which is vital for efficient gas exchange, consists of the alveolar epithelium, the interstitial space, and the capillary endothelium. The thinness of this membrane facilitates the rapid diffusion of oxygen and carbon dioxide between the air in the alveoli and the blood in the pulmonary capillaries. A thickness of around 0.5 μm ensures that the distance over which gases must diffuse is minimal, thereby optimizing the exchange process essential for respiration. This design is crucial for maintaining adequate oxygen levels in the bloodstream while allowing for the removal of carbon dioxide, supporting overall respiratory efficiency in the body.