Each Heartbeat is Initiated by the _______

Question

Each heartbeat is initiated by the _______.
A) sinoatrial (SA) node
B) bicuspid
C) atrioventricular (AV) node
D) AV bundle

Accepted Answer

The sinoatrial (SA) node is responsible for initiating each heartbeat. It is located in the right atrium of the heart and sends electrical signals to the atrioventricular (AV) node, which then sends them to the AV bundle and Purkinje fibers to cause contraction of the ventricles. The bicuspid valve is located between the left atrium and left ventricle and helps to prevent backflow of blood into the atrium during ventricular contraction.