sinoatrial node

synonym: sinuatrial node
https://doi.org/10.1351/goldbook.11220

Mass of specialized cardiac muscle cells ("pacemaker cells") that spontaneously depolarize to initiate rhythmic contraction of the heart.

Source:
PAC, 2016, 88, 713. (Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)) on page 805 [Terms] [Paper]