Question

Briefly explain about cardiac cycle. please Don't copy.

Answer 1

Hello Abhishek ...
_______________________________
This is your answer -
_______________________________
First of all let's know about Heart rate.

Normal Heart Rate - 72 times/min

Cardiac cycle has three events -

1. Atrial Systole - During atrial systole, atria contracts. Blood is pushed to the respective ventricles. During these conditions AV valves are in open state. Root of great veins are compressed and atria don't recieve blood. It's duration is 0.1 second.

2. Ventricular Systole - During ventricular systole, ventricles contract and atria relax, AV valves shut close and a "Lub" sound is produced. During these conditions *Isovolumetric contraction occurs and semilunar valve opens due to which blood eject in the great arteries. It's duration is of 0.3 second.
* Isovolumetric contraction - There is no change in the volume of the blood even though the ventricular wall is contracting.

3. Joint Diastole - All four chambers are in relaxed state. Beginning of ventricular Diastole is marked by the "Dubb" sound which occurs due to the closer of semilunar valve. After that AV valves open. It's duration is a 0.4 seconds.

VENTRICULAR FILLING -
✓ 70% filling is completed in joint diastole.
✓ 30% filling occurs during atrial systole.
✓ first 1/3 rd filling - rapid.
✓ second 1/3 rd filling - slow (diastasis).
✓ last 1/3 rd filling - rapid.

A complete cardiac cycle occurs in 0.8 second.
************************************************
Hope it will help you...
Best of luck...

Thanks !!!
Regards - Pratik Ratna