The Circulatory System

         Parts of the Circulatory System

        The Circulatory System is crucial to the life of humans. The main parts are blood, blood vessels, the heart, and the valves. The blood is the life sustaining fluid that flows in a continuous cycle though out the body. It is moved through the body because of the hearts pumping action. Blood distributes vitamins and enzymes to the cells, it carries hormones from the endocrine lands to the tissue and organs.
    There are 3 main parts to blood vessels, arteries, veins, and capillaries. The arteries carry oxygenated blood away from the heart to all parts of the body, while the veins carry blood back to the heart. Capillaries are tiny blood vessels that connect arteries to veins. The purpose of these veins are to carry the hormones that the glands release into the blood stream. 
         The heart acts as a pump, it pushes blood through the body. The blood vessels carry the blood to all of the tissues and organs in our body and keeps them alive. The blood vessels and arteries inside the heart are called coronary arteries and veins. The human heart has four chambers(left and right atrium, and left and right ventricle) and is two separate muscles that lie side by side. The heart is made up of special muscle called cardiac muscle
    The final part of the Circulatory System is the valves. There are 4 valves in the heart. The mitral(bicuspin) and the tricuspin allow blood to flow from the atria to the ventricles. While the aortic and pulmonary valves a control the blood leaving the heart through the ventricles.