BLOOD CARDIOVASCULAR SYSTEM LYMPHOID ORGANS
CARDIOVASCULAR SYSTEM
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
2 atria contracting while 2 ventricles relax, then vice versa.
|
|
|
1 atria contract while the other relaxes
|
|
|
2 ventricle and 1 atria contract, while the other atria relaxes
|
|
|
None of the above
|
Detailed explanation-1: -Both the atria and the ventricles undergo alternating states of systole and diastole. In other words, when the atria are in diastole, the ventricles are in systole and vice versa.
Detailed explanation-2: -Diastole (at right) normally refers to atria and ventricles at relaxation and expansion together-while refilling with blood returning to the heart.
Detailed explanation-3: -Atrial systole: lasts about 0.1 seconds-both atria contract and force the blood from the atria into the ventricles. Ventricular systole: lasts about 0.3 seconds-both ventricles contract, blood is forced to the lungs via the pulmonary trunk, and the rest of the body via the aorta.
Detailed explanation-4: -During a normal, healthy heartbeat, or what we call a cardiac cycle, the top two chambers of the heart, called the atria, contract simultaneously. Then, as they relax, the bottom two chambers, called the ventricles, contract.