Blood coming from all parts of the body is received by the (1)_____ of the heart by the way u the blood vessel called (2)____ Contraction of the right atrium sends blood to the (3)_____ this point, the (4)______ valves are open. While the valves are open. Contraction of the right ventricle forces blood to the (5)______ for oxygenation by the way of the (6)______ At this point, the (7)______ (8)______________ valves are closed to prevent back flow of the blood in the right atrium. From the lungs, oxygenated blood goes back to the (8)_____. of the heart via the blood vessels At this point, the Contraction of the left atrium forces blood to the (10)______. are open. Contraction of the left ventricle pumps blood to (12)______ by way of the (13)_______ called(9)_____ (11)_____ the largest artery. At this point, the (14)_____$ valves are open while the (15)______ revent the backflow of blood in the left atrium. are closed to prevent the backflow of blood in the left atrium SCIENCE ​