Circulatory+System+SancXi

The heart is an organ that pumps blood throughout your body. The heart has two loops that cross at its center. Blood travels from the heart to the lungs and back through the first loop. Blood travels from the heart throughout your body and back through the second loop. The blood travels through three kinds of blood vessels called arteries, capillaries, and veins. Arteries allow blood to travel away from the heart. The largest artery is called the aorta. The blood then flows into capillaries. From these tiny blood vessels, the blood flows into veins. Veins carry the blood back to the heart. The heart also has valves. Valves are flaps of tissue that prevent blood from flowing backward. Together arteries, capillaries, veins, and valves help blood travel through your body.

The circulatory system is very important. The circulatory system has four functions that make it so important. The four functions are it delivers materials, removes waste, regulates body temperature and fights disease. The body delivers materials through your blood. It transports chemical messengers, oxygen, and glucose to your body's cells. Your blood also removes waste. An example of this is the carbon dioxide you exhale. Your blood is in charge of bringing this carbon dioxide to your lungs. Changes in the amount of blood flow help regulate body temperature. Lastly, your blood contains cells that fight disease-causing microorganisms. Because of these four functions and the help it provides, the circulatory system is very important.