Heart. 



179 



MM. 

 pectinati 



Chorda 

 tendin. 



MM. 



pa,pillar. 



521. The Right Heart, laid open. 



The right auriculo- ventricular orifice is guarded by the tri cus- 

 pid valve, Talvula tricuspidalls ; the left by the mitral or bicus- 

 pid valve, Valvula Ucuspidalis. One set of the Columnae carneae are 

 the Musculi papittares, which are connected at their base with the ven- 

 tricular wall, and by the other end are attached to small tendinous 

 cords, Chordae tendineae, through which they are connected with the 

 segments of the auriculo-ventricular valve. 



The semilunar valves, Valvulae semilunares, three in number 

 on each side, guard the orifices of the aorta and pulmonary artery ; 

 they are attached by their convex margins, to the wall of each artery, 

 at its junction with the ventricle, the straight border being free. The 

 free margin of each presents at its middle, a small projecting fibro- 

 cartilaginous nodule, Nodulus s. Corpus Arantii, which is especially marked 

 at the semilunar valve of the aorta. The internal surfaces of all the 

 cavities of the heart are lined by the Endocardium, which is a thin, 

 connective tissue membrane covered with endothelium. 



Heitzmann, Atlas. II. 24 



