The dural venous sinuses are large channels located between the layers of the dura mater, which is the outermost membrane covering the brain and spinal cord. These sinuses collect deoxygenated blood from the brain and transport it back to the internal jugular veins, ultimately returning it to the heart. These sinuses play a crucial role in the brain's venous drainage system. They are lined with endothelium and do not have valves, allowing blood to flow freely. Major sinuses include the superior sagittal sinus, transverse sinus, and sigmoid sinus, each contributing to efficient blood circulation in the cranial cavity.