(a)[2]
Once the atria have filled with blood, atrial systole (contraction) occurs. State the events that happen to initiate and bring about atrial systole.
(b)[2]
State and explain how the heart’s structure makes it possible for the atria to contract before the ventricles.
(c(i))[3]
For each of the points E, F, G and H on Fig. 2.1, identify the valve involved and say whether it is open or closed.
(c(ii))[2]
Explain how Fig. 2.1 gives evidence that the left atrium wall and the left ventricle wall are not the same thickness.