Heart

[hart) [AS., heorte, heart]. A hollow, muscular organ, the function of which is to pump the blood through the ve els. It is enveloped by a serous sac called the pericardium, and consists of two symmetric halves, a right auricle and ventricle and a left auricle and ventricle. The right auriculoventricular orifice is guarded by the tricuspid valve; the left by a valve with two leaflets, the mitral. These valves are broad and thin, consisting of two layers of the lining membrane of the heart, the endocardium, separated by a slight amount of connective ti ue. To support them, thin chordae tendineae join their free margins to the muscles in the wall of the ventricle, the columnse carneae. The outlet of the right ventricle into the pulmonic artery, and the left into the aorta, are guarded by stout, short, tricuspid valves, the semilunar valves. H.-burn, a burning feeling at the epigastrium and lower part of the chest, caused by fermentation of the gastric contents. H., Fatty, a name given to two distinct pathologic conditions of the heart ti ue. In the first there is a true fatty degeneration of the muscular fibers of the heart; and in the second there is an increase in the quantity of sub pericardial fat — a fatty infiltration. 305