(a)[3]
Put the events into the right order, using 1 for the first event in the sequence. Events listed: • Purkyne tissue conducts the wave of excitation • atrioventricular node sends out a wave of excitation • atria contract • ventricles contract • sinoatrial node sends out a wave of excitation
(b)[2]
The wall of the left ventricle contains more cardiac muscle than the wall of the right ventricle. Explain why the walls of the left and right ventricles of the heart are different in thickness, in terms of their functions.