hen post the WORD document here. The minimum word count for this assignment is 4

hen post the WORD document here. The minimum word count for this assignment is 400 words
Describe what is happening in the
heart during artial contraction. Relate atrial contraction to the
electrical flow beginning at the SA node and ending at the Bundle if His.
Relate Starling’s Principle to atrial contraction. Why does blood not
drain directly into the ventricles? During atrial contraction, why does
blood not flow back into the vena cava or the Pulmonary vein? What are the
complications of a prolonged or shortened PRI?
here’s some info
Normally the impulse would start in the SA node, which acts
as the heart’s pacemaker. However, all the myocyte cells can act as a backup
during a failure. The SA node is at the rate of 60- 100 beats per minute.
Starting in the atrial chambers, the impulse continues to travel down the atria
to the AV node where it slows down. This gives the ventricles time to
“overfill”. If the AV node didn’t slow the impulse down. The Atria
and ventricles would pump at the same time, leading to inadequate profusion. If
the impulse starts in these cells the heart rate will look to be 55-60 bpm. The
AV node has a rate of 45-50 bpm. Next is the Bundle of His, just before the
electrical conduction system splits. It has a rate of 40-45 bpm, it splits into
the left bundle or right bundle branch, at 40-45 bpm. The last myocrates
sitting at the very bottom, is the purkinje fibers at 30-40 bpm.