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.
A marine scientist is dwarfed by what is being called the biggest shark ever caught on camera in a recent video taken near Mexico's Guadalupe Island. How did this 20-foot-long (6 meters) great white Internet sensation become such a behemoth?