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.As mentioned above, the circulatory system, which is also called cardiovascular system, has the role to supply the body cells and tissues with oxygen and nutrients, and therefore, the healthy circulatory system is vital for the survival.eart 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.