The microcirculation is the circulation of the blood in the blood vessels smaller than 200 microns interposed between the arterial and venous sections of the circulation. It is composed of arterioles, metarterioles, capillaries and venules. In addition to these blood vessels, the microcirculation also includes lymphatic capillaries and collecting ducts. The oxygenated blood is transported from the arterioles to the capillaries and then reaches the venules and veins. The main function of the microcirculation is the transport of oxygen and nutrients and the removal of carbon dioxide from the tissues. Another function is to regulate blood flow and tissue perfusion, thus influencing blood pressure.