Sinuses & Cranial Nerves

Sinuses of the dura mater are venous channels formed by the separation of its endosteal and meningeal layers, and are lined by a prolongation of the lining membrane of the veins, 1899. From 'The Treatise of the Human Anatomy and Its Applications to the Practice of Medicine and Surgery, Volume I' (1899). Cranial nerves are nerves that emerge directly from the brain, in contrast to spinal nerves, which emerge from segments of the spinal cord. In humans, there are traditionally twelve pairs of cranial nerves. Only the first and the second pair emerge from the cerebrum; the remaining ten pairs emerge from the brainstem. (Photo by VintageMedStock/Getty Images)