Venous sinuses are specialized channels in the brain that collect deoxygenated blood from the cerebral veins. They are located between the layers of the dura mater, which is the outermost protective layer of the central nervous system. These sinuses help drain blood from the brain and direct it toward the internal jugular vein. The main venous sinuses include the superior sagittal sinus, transverse sinus, and sigmoid sinus. They play a crucial role in maintaining proper blood flow and pressure within the cranial cavity. Dysfunction in these sinuses can lead to various medical conditions, including venous sinus thrombosis.