Friday, 22 July 2011

Closed Vs. Open Circulatory System

Oxygen is vital for life. This oxygen is diffused into the body cells via a blood circulatory system. This circulation not only helps carry oxygen to cells, but also carries nutrients and waste to and fro from the body tissues. There are two types of circulatory systems in animals. These include a closed circulatory system and an open circulatory system. Most vertebrates have a closed circulation, while an open circulation is found in arthropods and a few mollusks. Let us compare the closed vs open circulatory system and know more about each system in detail.
Closed Circulatory System
                                     A closed circulatory system is found in vertebrates as well as some of the higher invertebrates. The blood in the body flows through a system of arteries, veins and capillaries. Each organ in the body is surrounded by capillaries that provides nourishment, oxygen as well as takes away waste products. There are two major functions of a closed circulatory system. The pulmonary circulation helps carry deoxygenated blood from the organs to the lungs and the systemic circulation helps in carrying the oxygenated blood from the lungs to the various parts of the body. The blood moves through the veins and arteries due to a difference in pressure. This system suits larger animals perfectly as there is more area to be covered. As this is a closed system, the organs are not bathed in blood directly. The volume of the blood is lower than the blood in animals with an open circulatory system. The blood is pumped into the blood vessels with the help of the heart. This helps maintain the high pressure that is necessary for the blood to reach each and every extremity of the body.

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