Both open and closed circulatory system is concerned with the manner in which blood is distributed in the body, including animals and human beings. The circulatory system is very important among systems which are controlling the human body and how it functions. Some animals have a very simple blood circulation system, while others, for example, human beings, have a complex blood circulation structures. This tells a lot about the difference between open and closed circulatory systems. The open circulatory system, which is most common in invertebrates like crabs and cockroaches, is a simple type in which blood is shared directly with every organ of the body from the heart without having to pass through veins and arteries.
This is normally done at a lower pressure and requires less energy; this system implies that the animal having this type of circulation possesses a small body. The closed circulatory system, which is the complex type, requires blood to pass through vessels before it reaches the different body organs. This is common in large bodies, which needs a great amount of pressure for it to circulate blood adequately and effectively into various parts of the body. It is of two types; the pulmonary and the systemic circulation.