The transverse sinus (also lateral sinus; Latin: sinus transversus) is a dural venous sinus that passes laterally along the interior surface of the occipital bone.
The transverse sinus arises at the confluence of sinuses located at the internal occipital protuberance. The right transverse sinus is a direct continuation of the superior sagittal sinus, while the left transverse sinus is a continuation of the straight sinus.
The transverse sinus passes along the posterior margin of the tentorium cerebelli to the mastoid angle of the parietal bone. Further, it curves anterolaterally to reach the posterolateral side of the petrous part of the temporal bone. Then it continues as the sigmoid sinus.
On its course, the transverse sinus receives tributaries from the following brain regions:
- lateral temporal surface of the temporal lobe,
- basilar surface of the occipital lobe.
It also receives the inferior anastomotic vein (vein of Labbe), collecting minor veins from the temporal lobe.
The right transverse sinus collects venous blood from superficial parts of the brain, while the left transverse sinus is responsible for draining deep parts of the brain.