Cardiac cycle Flashcards
When does atrial contraction/systole occur?
After P wave
What does the P wave represent?
Atrial depolarisation during diastole
What does the QRS complex represent? How long does this last?
Depolarisation of ventricle
40ms
What is Isovolumetric contraction? What value does it reach?
Pressure increased in the Ventricle as they contract but volume stays the same
120mmHg
When Ventricle reaches maximum pressure what opens? What occurs
Aortic valve
Blood ejected at high speed
What does the T wave represent? What are they still doing?
Repolarisation of Ventricle
Still contracting
At what Ventricular pressure does the Aortic valve close?
80mmHg
How long does ventricular systole last?
0.3 seconds
How long does Ventricular diastole last?
0.5 seconds
What is occuring in the ventricles when the Aortic valve shuts? What % of maximum volume still remains?
Isovolumetric relaxation
25%
What happens to the Atrium during ventricular ejection?
Fills up with blood
What does the pressure increase from and to in the Left atrium during ventricular ejection? What % of this blood fills Ventricle? What does this mean in terms of atrial systole?
0-12mmHg
85-95%
Atrial contraction not vital for survival
What is it called when pLA=pLV?
Diastasis
What does a lower length of sarcomere mean when force is applied to it?
Lower maximal force
Maximal force of sarcomere when it is 80% its optimal length?
10%
What is Starlings law a measure of?
End Diastolic volume against Stroke volume
