Veins of the Head

Description

Centered on the internal occipital region, the confluence of sinuses (confluens sinuum, torcular Herophili) is shown where the superior sagittal sinus meets the straight sinus and drains laterally into the right and left transverse sinuses along the attached margin of the tentorium cerebelli. A horizontal section through the cranial cavity also exposes the inner table of the calvaria and the dural reflections that define the sinuses, with venous channels coursing posteriorly toward the sigmoid sinuses. Inferiorly and anterolaterally, the sigmoid sinuses continue as the internal jugular veins at the jugular foramen. Blue coding differentiates the dural venous sinuses and cerebral veins from surrounding bone. This posterior cranial venous crossroads matters because it is where flow patterns change with position, intracranial pressure, and obstruction, and it is a common site to discuss dural venous sinus thrombosis on CT venography or MRV. Small anatomical asymmetries are the rule, with one transverse sinus often dominant, a point that can be mistaken for pathology if you do not anchor your interpretation at the torcular and follow continuity into the sigmoid sinus and jugular bulb. A key teaching landmark. Use this asset in neuroanatomy and head and neck anatomy courses to teach venous drainage pathways, or in neuroradiology and neurosurgery materials addressing sinus thrombosis, posterior fossa approaches, and venous air embolism risk during sitting craniotomy positioning. It also suits textbook figures explaining the relationship of dural reflections to the cranial venous sinuses in a male adult model. Anatomical accuracy verified by SciePro's Medical Advisory Board.