Question

1
the heart contracts because of an electrical impulse. where in the heart does this impulse start?
multiple choice
left atrium
right ventricle
atrioventricular node
sinoatrial node

Explanation:

The sinoatrial (SA) node is the heart's natural pacemaker. It generates electrical impulses that initiate the heartbeat. The left atrium receives blood, the right ventricle pumps blood, and the atrioventricular node relays impulses (after the SA node starts them). So the impulse starts at the sinoatrial node.

Answer:

sinoatrial node