sinus venosus

Etymology
.

Noun

 * 1)  The first chamber of the heart in fish, amphibians, and reptiles, emptying into the right atrium.
 * 2)  An enlarged pouch that adjoins the heart, is formed by the union of the large systemic veins, and is the passage through which venous blood enters the heart in lower vertebrates and in embryos of higher forms.

Translations

 * Chinese:
 * Mandarin: 靜脈竇