This blood-air barrier is extremely thin (approximately 600 nm-2μm; in some places merely 200 nm) to allow sufficient oxygen diffusion, yet it is extremely strong.
Damage can occur to this barrier at a pressure difference of around 40 millimetres of mercury (0.053 bar).
Failure of the barrier may occur in a pulmonary barotrauma.
This can be a result of several possible causes, including blast injury, swimming-induced pulmonary edema, and breathing gas entrapment or retention in the lung during depressurization, which can occur during ascent from underwater diving or loss of pressure from a pressurized vehicle, habitat or pressure suit.
- Blood–brain barrier – Semipermeable capillary border that allows selective passage of blood constituents into the brain
- Blood–ocular barrier – A physical barrier between the local blood vessels and most parts of the eye itself
- Blood–retinal barrier – Part of the blood–ocular barrier that prevents certain substances from entering the retina
- Blood–testis barrier – A physical barrier between the blood vessels and the seminiferous tubules of the animal testes
- Blood–thymus barrier – A barrier formed by the continuous blood capillaries in the thymic cortex
- Pulmonary vein – The veins that transfer oxygenated blood from the lungs to the heart
Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Blood–air barrier.