Sinus venosus

• abstract: The sinus venosus is a large quadrangular cavity which precedes the atrium on the venous side of the chordate heart. In mammals, it exists distinctly only in the embryonic heart (where it is found between the two venae cavae); in nonmammalian chordates, however, the sinus venosus persists in the adult.

以上来源于: WordNet