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
Driving in the United States the flow of oxygen in the blood to the brain and other body parts. It affects people with heart disease and the central nervous system. Sulfur oxides are the cause of acid rain that damages the nature and human health. It particularly aggravates heart and lung diseases in children and the elderly. Nitrogen oxides are the main ingredients in the formation of acid rain and ground-level ozone that contributes to the global warming. Hydrocarbons are pollutants of air toxics and hazardous to the lung and other body parts. It causes cancer and birth defects. Finally, high-lead level in the air