Cuvier, Ducts of

the transverse blood vessels in vertebrates and man formed by the merging of the anterior and posterior cardinal veins; named after the French scientist G. Cuvier.

The ducts of Cuvier are well expressed in embryos, but in adult animals they are fully developed only in fish and caudate amphibians. The ducts open into the sinus venosus of the heart or into its corresponding section in the right auricle. In adult amphibians, the ducts of Cuvier are part of the anterior venae cavae, forming their terminal sections. In many adult mammals, including man, only the right duct is retained, as part of the right anterior vena cava; the left duct becomes a small cardiac vein, carrying blood from the walls of the heart to the right auricle.