These venous sinuses or Sinuses of the Duramater are the spaces between the meningeal and periosteal layers of the dura mater and are lined by endothelium. These receive the cerebral, meningeal and diploic veins and communicate with veins outside the cranium by means of emissary veins.
- The dorsal longitudinal (sagittal) sinus is situated in the convex border of the falx cerebri and receives the ascending cerebral veins.
- The ventral longitudinal sinus is smaller and is situated in the concave edge of the falx cerebri.
- The straight sinus is situated at the junction of the falx cerebri and tentorium cerebelli.
- The transverse sinuses are two in number. They are situated along the convex margin of tentorium cerebelli. The two sinuses are connected by a sinus communicans.
- The dorsal petrosal sinuses are the direct communication of the venae rhinalis posterior. They pass in the tentorium cerebelli and join the transverse sinuses at the internal opening of the temporal canal.
- The ventral petrosal sinuses lie along the lateral borders of the basioccipital enclosed in the thick dura closing the foramen lacerum.
- The cavernous sinuses are situated on the internal surface of the wings of the post sphenoid on either side of the sella turcica and are connected with each other by an intercavernous sinus behind the pituitary body.
- The occipital sinuses are situated in the dura on either side of the vermis cerebelli.
The basilar plexus is situated on the internal face of the basioccipital and is continuous with the plexus in the atlas.
Its chief emissary is the condyloid vein which brings it into communication with the ventral petrosal sinus.
