Question

Why is it important that the AV node relaying the electrical impulse moving from SA node and the atria to the ventricle.

Answer 1

You have to remember that the SA (Sino-Atrial) node sits in the UPPER portion of the RIGHT ATRIUM.

When it fires an impulse, it travels through both the right and left atrium (upper portion), which causes the chambers to contract. This would be noted as the "P wave" on an electrocardiogram (EKG or ECG).

After all this, the electric impulses will reach the AV (Atrio-Ventricular) node, which is located right above the ventricles. This is where the impulse will be held for a brief moment (PR interval) and this delay allows the right and left atrium to finish emptying out the blood into the two ventricles (BOTTOM 2 CHAMBERS). This "RELAY STATION" delays the stimulation of the ventricles long enough to allow the two atria to finish emptying out its contents (which is of course, blood).



Hope this helped your understanding. I didn't bother explaining the rest of the QRS and T segment on the ECG but if you need further explanations, feel free to ask.

Answer 2

thanks this helps a lot!

Answer 3

Medal worthy? :P