ANATOMY

Detailed explanation-1: -The sinus node continuously generates electrical impulses, thereby setting the normal rhythm and rate in a healthy heart. Hence, the SA node is referred to as the natural pacemaker of the heart.

Detailed explanation-2: -Sino-atrial node is also called of the heart. Q. Assertion :Sino-atrial node (SAN) is called the pacemaker. Reason: SAN generates the maximum number of action potentials and is responsible for initiating and maintaining the rhythmic contractions of the heart.

Detailed explanation-3: -Both nodes are capable of producing their own impulses. Though under normal conditions, when both are functional, SAN leads and AVN follows. That is, SAN activity determines the rate of heart beat. Hence it can be referred to as pace setter for the heart.

Detailed explanation-4: -Cells within the sinoatrial (SA) node are the primary pacemaker site within the heart. These cells are characterized as having no true resting potential, but instead generate regular, spontaneous action potentials.

Detailed explanation-5: -Single chamber. One lead attaches to the upper or lower heart chamber. Dual-chamber. Uses two leads, one for the upper and one for the lower chamber. Biventricular pacemakers (used in cardiac resynchronization therapy). 15-Dec-2021