Closed circulatory system occurs in

Closed circulatory system is usually high pressure system, in which blood flows in closed tubular structures called blood vessels ( arteries, veins and capillaries ). It is found in most of annelids, cephalopods , among the molluscs and all vertebrates including human beings. In this type of system these is no direct contact between body tissues and blood. This is more efficient as blood circulation is completed in short period .