(a(i))[1]
Name the valve marked V in Fig. $3.1$.
(a(ii))[2]
Using the chambers of the heart and the main blood vessels, describe how blood flows through the heart when the transverse section is shown in Fig. $3.1$.
(b)[2]
Identify which stage of the cardiac cycle is shown in Fig. $3.2$. Give a reason for your answer.
(c)[3]
An area of specialised muscle tissue in the wall of the right atrium, called the sinoatrial node, controls the rate and rhythm of the heartbeat. Describe the sequence of events that governs contraction of the ventricles during the cardiac cycle.