Carotid artery disease is caused by a buildup of plaques in arteries that deliver blood to your brain. Plaques are clumps of cholesterol, calcium, fibrous tissue and other cellular debris that gather at microscopic injury sites within the artery. This process is called atherosclerosis.
Great white sharks may not be the world's biggest sharks, since that title goes to the whale shark, but they are the planet's largest known predatory fish. Whale sharks and great whites couldn't be more different in temperament.
There are over 470 species of sharks and they have been living on Planet Earth for 420 million years. The smallest shark-the dwarf lantern shark-is only 17 centimeters (6.7 inches) in length, while the whale shark is the largest specie in the world, with approximately 12 meters (39 feet).