Wiggers Diagram Flashcards
What happens at the P wave?
Depolarization of the atria
What does atrial contraction coincide with on an EKG?
PQ segment
When does the S1 sound occur?
the AV valve closure
What is the QRS complex?
Depolarization of the ventricles
What occurs midway through the QRS complex?
Isovolumetric contraction of the ventricles
What does the beginning of systole coincide with on an EKG?
the ST segment
What does the T wave correspond with in the pressure and volume curves in wiggers diagram?
T wave is the end of systole (after majority of volume has left the ventricle). Pressure of the aorta starts to fall
When does S2 occur?
Isovolumic relaxation
When does the dichrotic notch occur?
The dichrotic notch occurs just before isovolumic relaxation
During diastole, when does the majority of the blood enter the ventricle?
Most enters during the beginning of diastole
Does the volume of the ventricle increase during atrial systole?
Yes, a little!
Does the pressure of the atria and the ventricle increase during atrial systole?
Yes
Why does the ventricular pressure stay high
To create the driving force to push the blood into the aorta and prevent back flow of blood
Why does isovolumic relaxation occur?
So that ventricular pressure can be decreased below atrial pressure (so that the AV valve can open and passive filling can occur).
