The Sinoatrial Node, or Cardiac Pacemaker, is ________

Question

The sinoatrial node, or cardiac pacemaker, is ________.
A) electrically active nodal tissue located in the wall of the left ventricle
B) embedded in the anterior two-thirds of the interventricular septum
C) able to cause the atria and ventricles to contract simultaneously
D) able to cause the cardiac muscle to begin to contract at the apex
E) embedded in the posterior wall of the right atrium, near the entrance of the superior vena cava

Accepted Answer

The sinoatrial node, or cardiac pacemaker, is embedded in the posterior wall of the right atrium, near the entrance of the superior vena cava. It is responsible for initiating the electrical impulses that regulate the heart rate and rhythm.