sinoatrial node
sinoatrial node
nounDefinition of SINOATRIAL NODE
: a small mass of tissue that is made up of Purkinje fibers, ganglion cells, and nerve fibers, that is embedded in the musculature of the right atrium of higher vertebrates, and that originates the impulses stimulating the heartbeat—called also S-A node, sinus node
Learn More About
Seen & Heard 
What made you want to look up sinoatrial node? Please tell us where you read or heard it (including the quote, if possible).
