Transverse Sinus

Origin

The transverse sinus commences at the confluence of venous sinuses at the level of the internal occipital protuberance. On the right side, the sinus can be seen as a direct continuation of the superior sagittal sinus, while the left transverse sinus is directly continuous with the straight sinus.

Course

On both sides the transverse sinuses travel along the attached margin of the tentorium cerebellum, in a groove, formed by the squamous part of the occipital bone and the mastoid angle of the parietal bone. Each sinus curves anteriorly and laterally, to reach the posterolateral end of the petrous bone. Here it leaves the tentorium cerebellum and turns down as the sigmoid sinus, to reach the jugular foramen, where it exits the cranial cavity as the internal jugular vein.

Transverse sinuses are triangular in section and of unequal sizes, with the one draining the superior sagittal sinus being the larger one.

Tributaries

The transverse sinuses receive the inferior cerebral, inferior cerebellar, diploic and inferior anastomotic veins. They are connected with the superior petrosal sinuses where they commence descending as the sigmoid sinuses. The sphenoparietal sinus sometimes curves backwards along the junction of squamous and petrous temporal bones to drain into transverse sinus.

Structures Drained

The transverse sinus drains the superior sagittal, occipital, and

straight sinuses.