What does the term 'sigmoid' in sigmoid sinus refer to?

The term 'sigmoid' in sigmoid sinus is derived from its characteristic curved or S-shaped appearance. This anatomical feature is essential in understanding the sinus's role and positioning within the cranial cavity. The sigmoid sinus is a venous channel located in the posterior cranial fossa, and its curvature plays a significant part in accommodating the flow of venous blood from the brain toward the jugular vein. Recognizing this curvature is crucial for clarity in identifying the sinus in neuroanatomical studies, as well as for surgical considerations when navigating the venous structures surrounding the brain.