1. During the atrial systole, the atrial muscles _______.   relax   contract   2. During the atrial systole, the openings of the pulmonary vein and the vena cava are _______.   open   closed   3. When the auricles of the heart contract, the ventricles relax, and vice versa.   True   False   4. The left auricle of the heart receives _______ blood from the lungs.   deoxygenated   oxygenated   5. The _______ of the heart pumps the blood up to the lungs only.   left ventricle   left auricle   right ventricle   right auricle   Hint Half-n-half Clue   6. Which fluid fills up the space between all human body cells?   intracellular fluid   extercellular fluid   intercellular fluid   extracellular fluid   Half-n-half Clue   7. In a normal adult, the red blood corpuscles are produced in the liver.   True   False