Why sa node called pacemaker of heart

The SA Node is located in the outer layer of the right atrium of the heart, near the superior vena cava. It is made up of a group of cells (myocytes) positioned on the wall of the right atrium, at the center of the heart and near the entrance of the superior vena cava. These cells contract at a rate of about 70-80 times per minute, which make up the natural heart beat.

It controls the heart rate by producing electrical impulses

It controls the heart rate by producing electrical impulses and later transmitting electrical signals through the heart muscle, creating the heart to contract and pump blood everywhere into the body. The heartbeat originates from the S.A. node and expands to the walls of auricles which contract.

atp is used for energy.

c. live where it’s cold and icy