378 



The Heart. 



Aorta ascendens 



Ostium venosum ventriculi sinistri 



Cuspis anterior valvulae tricuspidalis 

 Ostium venosum ventriculi dextri 



Cuspis 

 posterior 

 valvulae ~ ~ 

 tricuspidalis 



'Large 

 papillary muscle 



Trabeculae 

 carneae 



Arteria 

 pulmonalis 



_ Valvulae 

 semilunares 



. Conus 



arteriosus 



Crista 

 supraventricularis 



Sulcus longitudinalis 

 anterior 



Yentriculus sinister 



424. Right ventricle (venfriculus dexter) of a markedly 



distended heart, viewed from the right and above. 

 (The largest part of the right and anterior wall has been removed ; the atria have been removed.) 



Yentriculus dexter (continued) : the chordae tendineae of the anterior and posterior 

 cusps come from a large pajiillary muscle which stands up free from among the trabeculae carneae 

 at the junction of tht> conus arteriosus with the venous portion; besides this there is usually 

 one smaller papillary muscle between the septum and the inferior wall, as well as a very small 

 one on the septum just below the crista supraventricularis; the medial cusp receives many 

 chordae directly from the septum itself. The conus arteriosus is more tubular, has a fairly 

 smooth wall and goes over through the ostium arleriositm into the a. pulmonalis; at the 

 entrance to the latter are situated the valvulae semilunares arteriae pulmonalis anterior, 

 dextra, sinistra (semilunar valves of the pulmonary artery) (see p. 380). 



