Circulatory system the areas above the heart) and the inferior vena cava (roughly speaking from areas below the heart). These two great vessels empty into the right atrium of the heart. The heart itself is supplied with oxygen and nutrients through a small "loop" of the systemic circulation and derives very little from the blood contained within the four chambers. The general rule is that arteries from the heart branch out into capillaries, which collect into veins leading back to the heart. Portal veins are a slight exception to this. In humans the only significant example is the hepatic portal vein which
Dorsal metatarsal arteries Dorsal metatarsal arteries The arcuate artery of the foot gives off the second, third, and fourth dorsal metatarsal arteries, which run forward upon the corresponding Interossei dorsales; in the clefts between the toes, each divides into two dorsal digital branches for the adjoining toes. At the proximal parts of the interosseous spaces these vessels receive the posterior perforating branches from the plantar arch, and at the distal parts of the spaces they are joined by the anterior perforating branches, from the plantar metatarsal arteries. The fourth dorsal metatarsal artery gives off a branch which supplies the lateral side of the