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 is an umbrella term for any type of disorder that affects the heart. Heart disease means the same as cardiac disease but not cardiovascular disease.Cardiovascular disease refers to disorders of the blood vessels and heart, while heart disease refers to just the heart.ngina. Also known as angina pectoris, angina occurs when an area of heart muscle does not get enough oxygen. The patient experiences chest discomfort, tightness or pain. Angina is not technically a disease, but rather a symptom of coronary artery disease.