! Correctly sequence the pathway of blood flow through the heart, beginning with the venne cavae. Reset Blood enters right atrium from superior and interior venae cavae. 2 Blood in right atrium flows through right AV valve into right ventriclo. Contraction of right ventricle forces pulmonary valve open. 4Blood flows through pulmonary valve into pulmonary trunk Blood is distributed by right and left pulmonary arteries to the lungs, where it unloads CO and loads O. Blood returns from lungs via pulmonary veins to left atrium. Blood in left atrium flows through left AV valve into left ventricle. Contraction of left ventricle (simultaneous with stop) fordes aortic valve open. Blood flows through aortic valve into ascending aorta. 10 Blood in aorta is distributed to every organ in the body, where it unloads O and loads CO- Blood returns to heart via venae cavae.