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
American Academy of Otolaryngology–Head and Neck Surgery before adding "Head and Neck Surgery" to its name, yielding the American Academy of Otolaryngology–Head and Neck Surgery in 1980. In 1981, the American Council of Otolaryngology (ACO), which had formed in the 1960s for purposes outside the scope of the original educational organization (such as lobbying), merged with the American Academy of Otolaryngology–Head and Neck Surgery. American Academy of Otolaryngology–Head and Neck Surgery The American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) is one of the largest of the world's many professional associations for medical specialists, with nearly 12,000 specialists in the area of otolaryngology (otorhinolaryngology) - caring for