The elephant circulatory system is built to accommodate the nutritional and oxygen levels that is required. Despite its large size, the circulatory system of the elephant is
quite unexceptional. In keeping with the size of the animal, elephant hemoglobin has a higher oxygen affinity than that of other mammals. The heart of the African bull can weigh up to 28 kg, a size normal for such
a large animal.
A peculiarity exists with the ventricles of the elephant. The ventricles are separated at their apex. Also, there are paired venae cavae instead of
the usual single vein. These peculiarities are found in other penungulates and are probably primitive.
Due to their enormous size, arteries are supported by ridges of elastic fibers or muscles cells. The
veins are supported by having proportionately thicker walls than other mammals. The blood vessels of the elephant can achieve lengths of up to 350 cm, which require a high blood pressure in order to prevent their collapse if
they had thin walls.