intercavernous sinuses intercavernous sinuses the intercavernous sinuses are two in number, an anterior and a posterior, and connect the two cavernous sinuses across the middle line. intercavernous sinuses intercavernous sinusesdural veinsthe sinuses at the base of the skull. (visible as light blue circle at center.)detailsidentifierslatinsini intercavernosita98a12.3.05.117ta24862fma50773anatomical terminology the anterior passes in front of the hypophysis cerebri (pituitary gland), the posterior behind it, and they form with the cavernous sinuses a venous circle (circular sinus) around the hypophysis. the anterior one is usually the larger of the two, and one or other is occasionally absent.