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 the general term for all diseases and disorders that affect the heart and blood vessels, such as heart attack, stroke, coronary artery disease, and congenital or present at birth heart defects, as well as arrhythmia, angina and cardiomyopathy.Heart disease affects the body in several ways.eart disease. The heart is one of the most important organs in the human body. It is the part of the circulatory system along with the blood vessels and blood.