What is a venous sinus?

A venous sinus is a specialized type of blood vessel found in the brain and other parts of the body that collects deoxygenated blood. Unlike typical veins, venous sinuses are lined with endothelium and are formed by the separation of the layers of the dura mater, the outermost meningeal layer. They play a crucial role in draining blood from the brain and returning it to the cardiovascular system, particularly into the internal jugular veins. Common examples include the superior sagittal sinus and the transverse sinuses.