Confluence of Sinuses in a Cut Section of the Skull

Description

Posterior cranial anatomy is opened in cut section to expose the dural venous sinuses converging at the confluence of sinuses (torcular Herophili). The superior sagittal sinus courses in the midline along the attached margin of the falx cerebri to meet the straight sinus at the internal occipital protuberance, with the occipital sinus approaching inferiorly in the falx cerebelli. From the torcula, paired transverse sinuses run laterally along the tentorium cerebelli and continue anteroinferiorly as the sigmoid sinuses toward the jugular foramina, framed by the occipital bone, posterior cranial fossa contours, and the visible cranial base and orbits. This view matters when you need to teach or plan around venous outflow at the posterior midline. Midline suboccipital craniotomy, posterior fossa tumor approaches, and occipital bone instrumentation all carry risk of catastrophic hemorrhage if the torcula or a dominant transverse sinus is violated, and the confluence is also a reference point when interpreting MR venography for transverse sinus hypoplasia, dural sinus thrombosis, or elevated intracranial pressure patterns. Anatomical variability is the rule here, including right or left transverse sinus dominance and asymmetric flow channels. Use this illustration in neuroanatomy and head and neck anatomy coursework to anchor the dural reflections (falx and tentorium) to the venous sinuses, and in neurosurgery or neuroradiology teaching files to explain torcular relationships on CT, MRI, and venography. It also fits cranial trauma and operative atlas content where bony landmarks such as the internal occipital protuberance, jugular foramen region, and posterior cranial fossa margins guide safe dissection. Anatomical accuracy verified by SciePro's Medical Advisory Board.