Fill in the blanks.

(xv) The full form of SA node is _______.

Nodes of the heart:

1. There are two nodes present in the heart which help to run the cardiac cycle.
2. The two nodes of the heart are the SA node and AV node.
3. They both are present on the lower side of the right atrium.

SA node:

1. The SA node can be expanded as the Sino-Atrial node, which is also known as the pacemaker.
2. The SA node plays an inevitable role in the stimulation of the heartbeat by generating impulses to stimulate contraction.

The full form of SA node is Sino-Atrial node.