THORAX ABDOMEN AND PELVIS

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: -An electrical stimulus is generated by the sinus node (also called the sinoatrial node, or SA node). This is a small mass of specialized tissue located in the right upper chamber (atria) of the heart.

Detailed explanation-3: -SA node: The SA node (SA stands for sinoatrial) is one of the major elements in the cardiac conduction system, the system that controls the heart rate. This stunningly designed system generates electrical impulses and conducts them throughout the muscle of the heart, stimulating the heart to contract and pump blood.

Detailed explanation-4: -In the human and dog, in the centre of SA node, there are characteristic ‘P’ cells (or ‘typical nodal’ cells), which are believed to be the leading pacemaker cells [26]. The cells are not only small as reviewed above but also ‘empty’.