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
Coronary arteries Coronary arteries The coronary arteries are the arteries of the coronary circulation, which transports blood into and out of the cardiac muscle. They are mainly composed of the left and right coronary arteries, both of which give off branches. Coronary arteries can also be categorized as Epicardial (above the epicardium) and Microvascular (close to the endocardium). The left coronary artery arises from the aorta above the left cusp of the aortic valve and feeds blood to the left side of the heart. It branches into two arteries and sometimes a third branch is formed at the fork, known as a