Capillary glucose (such as in blood glucose monitoring), hemoglobin, pH and lactate Capillary blood sampling is generally performed by creating a small cut using a blood lancet, followed by sampling by capillary action on the cut with a test strip or small pipe. Contrary to a popular misconception, William Harvey did not explicitly predict the existence of capillaries, but he clearly saw the need for some sort of connection between the arterial and venous systems. He wrote, "…the blood doth enter into every member through the arteries, and does return by the veins, and that the veins are the vessels and
Great arteries of the aortic arch. The 5th pair of vessels only form in some cases without any known contribution to the final structure of the great arteries. The right 6th almost completely regresses with only the proximal part contributing to the base of the pulmonary arteries, while the left 6th forms the ductus arteriosus, which disappears after birth. Abnormalities in the development of the great arteries during embryonic development may lead to congenital cardiovascular defects, such as: Some of these defects can be asymptomatic and cause no complications in patients, with others being more severe and require immediate surgery right after