Sinus venosus

Sinus venosus
Interior of dorsal half of heart from a human embryo of about thirty days, frontal view. (Opening of sinus venosus labeled at center top.)
Human embryo with heart and anterior body-wall removed to show the sinus venosus and its tributaries. (Sinus venosus labeled at center left.)
Details
Carnegie stage9
SystemCardiovascular system
Identifiers
Latinsinus venosus cordis
TA98A12.0.00.016
TA23911
TEvenosus_by_E5.11.1.3.2.0.4, E5.11.1.5.1.0.1 E5.11.1.3.2.0.4, E5.11.1.5.1.0.1
FMA70303
Anatomical terminology

The sinus venosus is a large quadrangular cavity which precedes the atrium on the venous side of the chordate heart.

In mammals, the sinus venosus exists distinctly only in the embryonic heart where it is found between the two venae cavae; in the adult, the sinus venosus becomes incorporated into the wall of the right atrium to form a smooth part called the sinus venarum which is separated from the rest of the atrium by a ridge called the crista terminalis. In most mammals, the sinus venosus also forms the sinoatrial node and the coronary sinus.