The meninges are important supporting structures, which surround the brain within the skull. The outermost layer of the meninges is referred to as the dura mater. This layer lines the inner surface of the skull and has an important circulatory function. The dura mater is further divided into an outer and inner layer known as the periosteal layer and the meningeal layer respectively. Between these two layers are channels known as the dural venous sinuses, which drain blood from the brain and cranial bones. One of these sinuses is referred to as the straight sinus. This article will talk about the anatomy of the straight sinus, followed by any relevant clinical information.
The inferior sagittal sinus and the great cerebral vein (great vein of Galen) join together to form the straight sinus, which is 50 mm in length on average. This sinus also receives veins from the occipital lobes and the superior surface of the cerebellum. It is located between the two dural layers at the junction of the tentorium cerebelli and the falx cerebri, which are folds of the dura mater. The straight sinus ends at the internal occipital protuberance, a bony landmark on the cranium, and empties into the transverse sinus contributing to the formation of the confluence of sinuses – a dilatation of the venous channel at the level of the internal occipital protuberance, where the superior sagittal, straight, occipital and right/left transverse sinuses converge. After the confluence of sinuses the transverse sinuses become sigmoid sinuses (right/left) that open into the bulb of the internal jugular vein.