In high school, you probably learned that trigonometric functions – like sine, cosine and tangent –can be derived, geometrically, from a circle (hence why trig functions are also known as “circular” ...

Our heart and lungs circulate oxygen throughout our blood vessels to keep cells alive. At the center of the circulatory system is the heart, which works with the lungs to constantly keep the body ...

Your heart is a muscular organ about the size of a fist located in the chest cavity close to the lungs. It functions as a pump, consistently circulating blood throughout the body. The heart also helps ...

Scientists have created images of the heart's muscular layer that show, for the first time, the connection between the configuration of those muscles and the way the human heart contracts. More ...