A small body of specialized muscle tissue in the wall of the right atrium of the heart that acts as a pacemaker by producing a contractile signal at regular intervals.
More example sentences
- This activity arises not from excitatory nerve fibres, but spontaneously within the heart itself from a small clump of pacemaker cells near the point where the vena cava joins the right atrium: the sino-atrial node.
- The classical concept of the source of cardiac rhythm is that it originates from the sino-atrial node.
- Procoralan exclusively reduces heart rate by a specific action on the sino-atrial node.