Explain The Cardiac Cycle And How The Valves Control The Flow Of Blood Through The Heart

Question 1

Name the valves in the heart?

Answer 1

Atrioventricular valves found between the atrium and ventricles.
Semi-lunar valves found between the ventricles and the aorta / pulmonary artery

Question 2

What is cardiac output?

Answer 2

The volume of blood pumped out the heart in one minute (rate of blood flow).

Question 3

What’s the cardiac output equation?

Answer 3

CO = SV x HR

Question 4

Explain the cardiac cycle?

Answer 4

1. Atrial systole ( atriums contract and ventricles are fully relaxed, AV valves open and blood into ventricles)
2. Ventricular systole (atrium relaxed and ventricles being to contract. AV valves close, semi lunar open and ventricles contract. Blood to rest of the body)
3. Complete cardiac diastole (ventricles start to relax and AV valves close, blood fill atrium. Atrium then start to contract, AV valves open and blood fill relaxed ventricles)
   REPEAT.

Question 5

Explain the electrical system of the heart?

Answer 5

Sinoatrial node (SA) node depolarise at a fast rate and set the rate of contraction.
Depolarisation spreads through atria to AV node.
It then travels down the bundle of his, down the bundle branches, through the Purkinje fibres. The PF carry the electrical activity through the ventricular myocardium.