| QUESTION | ANSWER | EXPLANATION |
| During the atrial systole, the openings of the pulmonary vein and the vena cava are _______. | closed | During the atrial systole, the openings of the pulmonary vein and the vena cava are closed. During the ventricular systole, the openings of the pulmonary artery and the aorta are open. |
| Which fluid fills up the space between all human body cells? | intercellular fluid | The intercellular fluid fills up the space between all human body cells. |
| The left auricle of the heart receives _______ blood from the lungs. | oxygenated | The left auricle (also called left atrium) of the heart receives oxygenated blood from the lungs through the pulmonary vein. |
| The _______ of the heart pumps the blood up to the lungs only. | right ventricle | The right ventricle of the heart pumps the blood up to the lungs only. This blood gets oxygenated in the lungs and is then pumped into the left auricle by the pulmonary vein. |
| The process of circulation of blood in the heart begins with the _______ of the auricles of the heart. | contraction | The process of circulation of blood in the heart begins with the contraction of the auricles of the heart. |
| During the atrial systole, the atrial muscles _______. | contract | During the atrial systole, the atrial muscles contract. |
| When the auricles of the heart contract, the ventricles relax, and vice versa. | True | When the auricles of the heart contract, the ventricles relax, and vice versa. |
| Plasma is a constituent of blood. | True | Plasma is the yellow-colored, alkaline constituent of blood. |
| During the ventricular systole, the blood enters the ventricles. | False | During the ventricular systole, the blood enters the auricles. During the atrial systole, the blood enters the ventricles. |
| During the ventricular systole, the semilunar valves are closed. | False | During the ventricular systole, the semilunar valves are open to allow the flow of blood into the pulmonary artery and the aorta. During the atrial systole, the semilunar valves are closed to prevent the flow of blood back into the ventricles. |
| In a normal adult, the red blood corpuscles are produced in the liver. | False | In a normal adult, the red blood corpuscles are produced in the bone marrow. In an embryo, they are produced in the liver and the spleen. |
| The inferior vena cava carries blood from the upper parts of the body to the heart. | False | The inferior vena cava (also called posterior vena cava) carries deoxygenated blood from the lower (posterior) parts of the body (e.g., abdomen, legs, etc.) |
| The cardiac veins carry blood to the walls of the heart. | False | The cardiac veins collect blood from the walls of the heart. |
| With reference to the heartbeat, the word 'systole' refers to a relaxation phase whereas the word 'diastole' refers to a contraction phase. | False | With reference to the heartbeat, the word 'systole' refers to a contraction phase whereas the word 'diastole' refers to a relaxation phase. |
| The right auricle of the heart receives oxygenated blood. | False | The right auricle of the heart receives deoxygenated blood from all parts of the body through the vena cava. The left auricle receives oxygenated blood through the pulmonary veins. |
