This is the groove that houses the sigmoid dural venous sinus. It forms as a distinct groove on the internal surface of the mastoid temporal bone. Its course follows a gradual bend from the superoposterior angle of the bone, near its junction with the parietal and occipital bones, to the antero-inferior corner of the bone where it joins the jugular process of the occipital bone.

Sulcus is Latin for groove or a long, shallow, open channel in the bone. Sigmoid means shaped like the letter "S." It comes from the Greek letter "S" or sigma. Sinus is Latin for a curve, fold, bay, or gulf. In anatomy it can describe anything from a large, hollow cavity to a concave groove-like channel.

Sillon du sinus sigmoïde