Why does blood from the right ventricle have low pressure?

What are the three stages of the cardiac cycle in order?

What happens during atrial systole?

What valve connects the arteries and ventricles?

What are the valves called in the aorta and pulmonary artery?

What happens during ventricular systole?

What do the elastic tissues in the walls of the ventricles do?

What causes the "lub-dub" sound of the heart beat?

What keeps the valves from turning inside out?