Definition of sinus node
: a small mass of tissue that is embedded in the musculature of the right atrium of higher vertebrates and that originates the impulses stimulating the heartbeat
First Known Use of sinus node
Rhymes with sinus node
Medical Definition of sinus node
Learn More about sinus node
Medical Dictionary: Definition of "sinus node"
Seen and Heard
What made you want to look up sinus node? Please tell us where you read or heard it (including the quote, if possible).