"sinoatrial node." YourDictionary, n.d. Web. 18 September 2018. <http://www.yourdictionary.com/sinoatrial-node>.
sinoatrial node. (n.d.). Retrieved September 18th, 2018, from http://www.yourdictionary.com/sinoatrial-node
A small mass of specialized cardiac muscle fibers located in the posterior wall of the right atrium of the heart that acts as a pacemaker by generating at regular intervals the electric impulses of the heartbeat. Also called sinoauricular node . Also called sinus node .