Pulmonary vein three and five in the healthy population. The two left lobar veins may be united as a single pulmonary vein in about 25% of people; the two right veins may be united in about 3%. The pulmonary veins play an essential role in respiration, by receiving blood that has been oxygenated in the alveoli and returning it to the left atrium. As part of the pulmonary circulation they carry oxygenated blood back to the heart, as opposed to the veins of the systemic circulation which carry deoxygenated blood. A rare genetic defect of the pulmonary veins can cause them to
Blood irradiation therapy sources. It is used only for ultraviolet blood irradiation, that involves drawing blood out through a vein and irradiating it outside of the body. Though promoted as a treatment for cancer, a 1952 review in the "Journal of the American Medical Association" and another review by the American Cancer Society in 1970 concluded the treatment was ineffective. Stephen Barrett, writing for Quackwatch, lists ultraviolet blood irradiation therapy as a questionable treatment. Blood irradiation therapy Blood irradiation therapy is a procedure in which the blood is exposed to low level red light (often laser light) for therapeutic reasons. Most research on