With water, colder and saltier equals denser. At the earth's poles, when water freezes, the salt doesn't necessarily freeze with it, so a large volume of dense cold, salt water is left behind. When this dense water sinks to the ocean floor, more water moves in to replace it, creating a current. The new water also gets cold and sinks, continuing the cycle. Incredibly, this process drives a current of water around the globe.
Medical Definition of HEART DISEASE. : an abnormal organic condition of the heart or of the heart and circulation.See heart disease defined for kids.ADVERTISEMENT.edical Definition of HEART DISEASE. : an abnormal organic condition of the heart or of the heart and circulation.
Heart disease: Any disorder that affects the heart. Sometimes the term heart disease is ... Heart muscle: A type of muscle with unique features only found in the heart. The heart mus... Heart rate: The number of heartbeats per unit of time, usually per minute. The heart rate ...he following are health and medical definitions of terms that appear in the Heart Disease article. Abdomen: The belly, that part of the body that contains all of the structures between the... Abdominal: Relating to the abdomen, the belly, that part of the body that contains all of ... Abdominal pain: Pain in the belly.