/Animals have complete circulation and incomplete circulation/
/Los animales tengan la circulación completa y la circulación incompleta/
In these circulatory systems, oxygen-rich blood never mixes with low-oxygen blood. This is because the circulatory system of these animals has a heart with well-defined chambers.
The meeting place is the heart. Non-oxygenated blood comes from other parts of the body and oxygenated, logically, comes from the lungs.
