Describe the structure of the heart

What are the valves held in place by?

What is the role of valves?

Complete the sentences:
If there is a __________ pressure behind a valve, it is forced open. If there is a higher pressure in front of the valve, it is forced _________. This means that the flow of blood is _____________ - it only flows in ______ ____________

What is the role of the cardiac cycle?

Within the human heartbeat, you can hear a 'lub-dub' sound. What is the 'lub' and the 'dub' sound caused by?

What are the 3 stages of the cardiac cycle?

What happens during atrial systole?

What happens during ventricular systole?

What happens during diastole?