1. | is derived from embryonic endoderm. |
2. | is situated in the thoracic cavity, in between the two lungs. |
3. | has the size and shape of a baseball. |
4. | is protected by a single walled membranous bag, pericardium. |
I: | The opening between the right atrium and the right ventricle is guarded by the tricuspid valve. |
II: | A bicuspid or mitral valve guards the opening between the left atrium and the left ventricle. |
III: | The openings of the right and the left ventricles into the pulmonary artery and the aorta respectively are provided with the semilunar valves. |
1. | all the four chambers of heart can never be in a relaxed state simultaneously. |
2. | as the tricuspid valve gets open, blood from the pulmonary artery flows into the right ventricle. |
3. | all the four chambers of heart can never be in a contracted state simultaneously. |
4. | as the bicuspid valve gets open, blood from the aorta flows into the left ventricle. |
1. | 10 percent | 2. | 30 percent |
3. | 50 percent | 4. | 70 percent |
I: | closure of semilunar valves occurs. |
II: | the tricuspid and bicuspid valves are pushed open. |
1. | 60 | 2. | 75 |
3. | 72 | 4. | 100 |
I: | The first heart sound (lub) is associated with the opening of the tricuspid and bicuspid valves. |
II: | The second heart sound (dub) is associated with the opening of the semilunar valves. |
Assertion(A): | The cardiac output of an athlete will be much higher than that of an ordinary man. |
Reason(R): | The body has the ability to alter the stroke volume as well as the heart rate and thereby the cardiac output. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | (A) is True but (R) is False. |
3. | Both (A) and (R) are True but (R) is not the correct explanation of (A) |
4. | (A) is False and (R) is True. |