The main objective of the circulatory system is  transporting oxygenated (rich saturation of oxygen) blood around  the body. The de-oxygenated blood enters through the vena cava and  into the right atrium of the heart. It then goes to the right  ventricle, directly below the atrium.
Pyramid of the Sun. Less than half a mile south of the Pyramid of the Moon is the Pyramid of Sun. At a height of more than 200 feet (63 meters) and a base more than 730 feet (225 meters) long on each side, this pyramid is one of the largest structures created in the pre-Columbian New World. It would have been completed around 200 AD.
The Pyramid is now 447*4 feetin height andwas or-iginally 471. Each side of thebase measures now 690^ feet,originally 707 M. The twolower courses of thecasing were ofgranite, some blocks of which are still to be seen on the west side. All the upper part was of Tura limestone, much of which still remains.