sinoatrial node

American  

[sahy-noh-ey-tree-uhl, sahy-] / ˈsaɪ noʊˈeɪ tri əl, ˌsaɪ- /

noun

Anatomy.

1. a small mass of tissue in the right atrium functioning as pacemaker of the heart by giving rise to the electric impulses that initiate heart contractions.

---

sinoatrial node Scientific  

/ sī′nō-ā′trē-əl /

1. A small mass of specialized cardiac muscle fibers that acts as a pacemaker by initiating and maintaining normal heartbeat and cardiac rhythm. It is located in the right atrium.

---

Etymology

Origin of sinoatrial node

1920–25; sino- + atrial ( def. )

Example Sentences

The internal pacemaker starts at the sinoatrial node, which is located near the wall of the right atrium.

From Textbooks • Jun. 9, 2022

It is the excitation of cardiac muscle cells at the atrioventricular node followed by the sinoatrial node.

From Textbooks • Jun. 9, 2022

It is an electrical impulse that starts in cardiac muscle cells at the sinoatrial node.

From Textbooks • Jun. 9, 2022

Mammals also have a specialized group of cardiac fibers located in the walls of their right atrium called the sinoatrial node, or pacemaker, which determines the rate at which the heart beats.

From Textbooks • Jan. 1, 2015

TBX18 is normally active in embryos, where it triggers, among other things, the formation of the heart’s rhythm keeping centre, the sinoatrial node.

From Forbes • Jul. 17, 2014