The heart receives its own supply of blood from a network of arteries, called the coronary arteries. Two major coronary arteries branch off from the aorta near the point where the aorta and the left ventricle meet:
Walton, Ernest Thomas Sinton - Student Encyclopedia (Ages 11 and up) (1903-95), Irish physicist. Born in County Waterford, Ireland, Walton, with Sir John D. Cockcroft, received the 1951 Nobel prize in physics for the development of the first nuclear-particle accelerator.
After the discovery of the neutron in 1932, models for a nucleus composed of protons and neutrons were quickly developed by Dmitri Ivanenko and Werner Heisenberg. Almost all of the mass of an atom is located in the nucleus, with a very small contribution from the electron cloud.