1. In a normal adult, the red blood corpuscles are produced in the liver.   True   False   2. During the atrial systole, the atrial muscles _______.   relax   contract   3. The inferior vena cava carries blood from the upper parts of the body to the heart.   True   False   4. During the ventricular systole, the semilunar valves are closed.   True   False   5. The cardiac veins carry blood to the walls of the heart.   True   False   6. During the atrial systole, the openings of the pulmonary vein and the vena cava are _______.   closed   open   7. Plasma is a constituent of blood.   True   False