1. Pericardium is the double-walled membranous covering that protects the heart.   True   False   2. The spleen is located behind the stomach.   True   False   3. Blood aids in regulating the body temperature.   True   False   4. The pulse rate decreases during strenuous physical work.   True   False   5. A portal vein begins in the form of capillaries and ends in the form of capillaries too.   True   False   6. The coronary arteries originate from the base of the aorta.   True   False   7. There are four kinds of valves in the heart.   True   False