Blood coming from all parts of the body is received by the _________ of the heart by way of the blood vessel called (2) ___________ Contraction of the right atrium sends blood to the (3) _________. At this point, the (4) _____________ valves are open. Contraction of the right ventricle forces blood to the (5) ________ for oxygenation by way of the (6) __________ At this point, the (7)____________ valves are open, while the (8) _________ valves are closed to prevent the back flow of blood in the right atrium. From the lungs, oxygenated blood goes back to the (8) of the heart via the blood vessels called (9)_________ Contraction of the left atrium forces blood to the (10) ___________ . At this point, the (11) __________ are open. Contraction of the left ventricle pumps blood to (12) ________ by way of the (13) ___________, the largest artery. At this point, the (14) ___________ valves are open while the (15) are closed to prevent the backflow of blood in the left atrium.​