fig 3.

Illustration of normal veins and venous sinuses of skull base demonstrates anterior condylar vein originating at junction of inferior petrosal sinus and jugular bulb and then coursing through hypoglossal (anterior condylar) canal. ICA, internal carotid artery; APA, ascending pharyngeal artery; Mbr (APA), meningeal branch of the ascending pharyngeal artery; ACV, anterior condylar vein; PCV, posterior condylar vein; BP, basilar plexus; SPS, superior petrosal sinus; IPS, inferior petrosal sinus; MS, marginal sinus; SS, sigmoid sinus; IJV, internal jugular vein. (Printed with permission from Mayfield Clinic.)