Emissary veins passing through the foramen ovale, jugular foramen, foramen lacerum, and hypoglossal canal. Because the emissary veins are valveless, they are an important part in selective brain cooling through bidirectional flow of cooler blood from the evaporating surface of the head. In general, blood flow is from external to internal but the flow can be altered by increased intracranial pressure. A type of emissary vein goes through the sphenoidal emissary foramen inferior to the zygomatic arch with the cavernous sinus on the inside of the skull. This is an important route for spread of infection because cranial nerve VI and the
History of the location of the soul the heart does not need the brain to move. Galen recognized the importance of both the heart and the brain in the proper functioning of a human but saw these as two distinct system governed separately. Therefore there are two souls in combat, the brain representing the logical soul and driving logical being, the heart representing spirited actions of movement and impulse constantly at odds with each other and supplied by different supporting systems. Galen states the "liver is the archai" or the source of the veins and blood of the body and is therefore important in regards to the