1. AS Level Physical
Education
PE 1 – The articulate Performer
Cardiac Cycle
Karen Vaughan Jones

2. Outcomes
 By the end of this lesson you should
know:
 The function of the cardiac cycle during
blood transportation
 Understand the specific details of a
systole and diastole
 Understand the conduction system of
the heart

3. The cardiac cycle
 As the blood travels around the heart a
cardiac cycle occurs
 A cardiac cycle occurs in ONE
COMPLETE HEARTBEAT
 This includes the filling of the heart
with blood – DIASTOLE
 Also includes the emptying of the blood
in to the arterial system – SYSTOLE

4. Stages of the cardiac cycle
 Each cycle takes 0.8 seconds and on average 72
times per minute
 Four stages to each heartbeat
 Diastole – atrial and ventricular
 Systole – atrial and ventricular
 Each stage is dependent on whether the
chambers of the heart are filling with blood
while the heart is relaxing – Diastole
 Or whether they are emptying which occurs
when the heart is contracting - Systole

5. Activity
 Using the notes provided – summarise
the four stages of a cardiac cycle on
the ohp sheet
 Recap:
3. Atrial diastole
4. Ventricular diastole
5. Atrial systole
6. Ventricular systole

6. 1. Atrial diastole
 Upper chambers of the heart are filled
with blood returning from:
 The body via the venae cavae to the
right atrium
 The lungs via the pulmonary vein to the
left atrium
 The atrio-ventricular valves are shut at
this moment, but as volume of blood
increases the AV valves open to allow…

7. Atrial diastole

8. 2. Ventricular diastole
 As soon as the atrio-ventricular valves
open the second stage of the cardiac
cycle occurs
 As the ventricles fill with blood the
semi-lunar valves remain shut
 The atria now contract

9. Ventricular diastole

10. 3. Atrial systole
 As the atria contract, atrial systole
occurs which ensure all the blood is
emptied in to the ventricles
 The pressure increases – AV valves shut

11. Atrial systole

12. 4. Ventricular Systole
 Ventricular pressure increases – overcomes
the pressure in the aorta and the pulmonary
artery
 Semi-Lunar valves open – ventricles contract
 Blood from the right ventricle- pulmonary
artery
 Blood from the left ventricle – aorta
 Once completed – SL valves close
 Cycle is complete

13. Ventricular systole

14. Timings of systole and diastole

16. Conduction system
 The conducting system relies on
transmissions of impulses and consists
of cardiac muscle cells and conducting
fibres that are specialised for initiating
impulses and rapid conduction
throughout the heart.
 They initiate the normal heartbeat and
co-ordinate contraction of the heart
chambers

17.  Unlike skeletal muscle – heart produces
its own impulse – myogenic
 Begins at the SA node sino atrial