Q1. The ______ brings blood back to the right atrium of heart from the upper body. The ______ carries blood back to the right atrium from the lower body. The ______ carries blood from the right ventricle to the ______. The ______ carries blood from the ______ to the left atrium. The circulation of the blood from the right ventricle via the lungs and back to the ______ is termed as the ______ circulation. The ______ serves the rest of body. The ______ brings blood away from the left ventricle; it is as big as a garden hose. The ______ valve, as well termed as the ______ valve, prevents backflow of blood from the left ventricle to the left atrium. The ______ prevents backflow of blood from the right ventricle to the right atrium. The ______ valve prevents backflow of blood from aorta to the left ventricle. The ______ valve prevents backflow of blood from the pulmonary artery to the ______.

Q2. Key portions of the cardiac circulation that provides blood to the wall of the _____, are the ______, the ______, the ______ and the ______. Lack of blood to the heart wall can outcome in ______ or in ______.

Q3. The heart beat is controlled by ______ of the heart. The ______ node, as well termed as the pacemaker of the heart, starts the nerve impulse which spreads via the heart. This starts the contraction of the atria. The ______ delays the impulse a short time, allowing time for the blood to fill the ______. Then the message rapidly travels down the septum of the heart in ______. Whenever the message travels via the ______, the ventricle walls contract.