Super Devouring System

Circulation refers to the movement of substances such as gases and nutrients within your blood vessels as well as cavities throughout your body. The circulatory systems can be closed (as in fish and mammals) or open (as in insects). In case of closed circulator systems, you may notice single circulatory systems with two-chambered heart. In some cases, you may notice double circulatory systems with a four-chambered heart. [ 476 more words ] Super Devouring System

http://health100net.com/double-circulatory-system-2/

Double Circulatory System Circulation refers to the movement of substances such as gases and nutrients within your blood vessels as well as cavities throughout your body. The circulatory systems can be closed (as in fish an…health100net.com