A, The veins from the region of the tonsil empty into the inferior vermian veins that ascend toward the sinuses in the tentorium. B, Gentle retraction of the cerebellar tonsils exposes the veins of the cerebellomedullary fissure crossing the inferior medullary velum. C, The cerebellar tonsils have been removed. The tela on the left side has been removed. The veins of the cerebellomesencephalic fissure cross the inferior medullary velum to join the veins in the cerebellopontine angles, which empty into the superior petrosal veins. The medial end of the veins of the cerebellomedullary fissure anastomose with the veins around the tonsil. D, A portion of the left half of the cerebellum has been removed. The inferior hemispheric veins from the suboccipital surface ascend and cross the junction of the suboccipital and tentorial surfaces to course on the posterior part of the tentorial surface, where they often form common stems with the superior hemispheric veins from the posterior part of the tentorial surface before emptying into the tentorial sinuses. (Images courtesy of AL Rhoton, Jr.)