sinus venosus(redirected from Sinus venarum)
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The first chamber in the heart of fish, amphibians, reptiles, and the embryos of birds and mammals, which receives blood from the veins and contracts to force the blood into the atrium.
[New Latin sinus vēnōsus : Medieval Latin sinus, sinus + Latin vēnōsus, venous.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.