sinus node


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

Examples of sinus node in a Sentence

Recent Examples on the Web Hearts beat when the sinus node, a small mass of tissue in the right upper chamber, transmits an impulse to the heart cells. Michael Ciaglo, National Geographic, "From tear gas to rubber bullets, here’s what ‘nonlethal’ weapons can do to the body," 5 June 2020 Over the course of a day, a person’s heart beats about 100,000 times, and each beat begins with an electrical signal generated in the sinus node in the heart’s upper right chamber. Emily Sohn, Washington Post, "Everyone has heart palpitations, but for some it can be serious," 7 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'sinus node.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of sinus node

1937, in the meaning defined above

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Time Traveler for sinus node

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The first known use of sinus node was in 1937

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Cite this Entry

“Sinus node.” Dictionary, Merriam-Webster, Accessed 29 Oct. 2020.

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More Definitions for sinus node

sinus node


Medical Definition of sinus node

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