The orifice of superior thyroid vein to the internal jugular vein in human fetuses.

In this study an attempt was made to define the ways of the orifice of the superior thyroid gland to the internal jugular vein in human fetuses, basing on corrosion casts of blood vessels. It was found that most frequently, i.e. in 44% of cases, the superior thyroid gland formed bilaterally multi-level anastomoses with the facial vein and lingual vein before the orifice to the internal jugular vein. In addition, anastomoses of the three mentioned veins into a common venous trunk and non-anastomotic course of the superior thyroid vein were found.