Fill in the Blank Questions 37.In a ___________ circulatory system, blood is pumped by a heart through blood vessels. 38._________________ are blood vessels that move blood away from the heart. 39._________________ are tiny blood vessels leading away from capillaries to veins. 40.Once inside the lymphatic system, tissue fluid is called ______________. 41.The heart valve guarding the entrance to the aorta is the _________ valve. 42.The veins leading from the lungs to the heart are the ____________ veins. Â Â