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physiology IV > Wiggers Diagram > Flashcards

Flashcards in Wiggers Diagram Deck (14):
1

What happens at the P wave?

Depolarization of the atria

2

What does atrial contraction coincide with on an EKG?

PQ segment

3

When does the S1 sound occur?

the AV valve closure

4

What is the QRS complex?

Depolarization of the ventricles

5

What occurs midway through the QRS complex?

Isovolumetric contraction of the ventricles

6

What does the beginning of systole coincide with on an EKG?

the ST segment

7

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

8

When does S2 occur?

Isovolumic relaxation

9

When does the dichrotic notch occur?

The dichrotic notch occurs just before isovolumic relaxation

10

During diastole, when does the majority of the blood enter the ventricle?

Most enters during the beginning of diastole

11

Does the volume of the ventricle increase during atrial systole?

Yes, a little!

12

Does the pressure of the atria and the ventricle increase during atrial systole?

Yes

13

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

14

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).