space+intervening
131Pericardium — The conical sac of fibrous tissue that surrounds the heart and the roots of the great blood vessels. The pericardium’s outer coat (the parietal pericardium) is tough and thickened, loosely cloaks the heart, and is attached to the central part of… …
132field — A central concept of physical theory. A field is defined by the distribution of a physical quantity, such as temperature, mass density, or potential energy, at different points in space. In the particularly important example of force fields, such …
