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 (cardiovascular) means you are having problems with your heart and the blood vessels throughout your body. Over time, the blood vessels that bring blood to the heart and brain can become blocked from a buildup of cells, fat and cholesterol. This reduces blood flow to the heart and brain and can cause heart attacks and strokes.