374 



The Heait. 



Aorta ascendens 



Valvula venae cavae 

 [inferioris, Eustachii] 



Musculi pectinati_ 



Foramen venae 

 minimae [Thebesii]'^ ^ 



Septum I 



membranaceum i 



ventriculormn [ 



Cusp is 

 posterior valvuhie 

 tricuspidalis ~ 

 Cuspis 

 medialis valvulae 

 tricuspidalis 



\ 



Atrium sinistrum 



Valvula semilunaris 



sinistra aortae 



Large 

 papillary muscle' 



Anterior 

 -papillary muscle 



Posterior 

 papillary muscle 



Septum musculare 

 ventriculorum 



>- / Ventriculus sinister 



Trabeculae carneae 



420. Transverse section through a distended heart 



approximately parallel to the facies diapliragmatica. 

 (Inferior half of the section, viewed from above.) 



The septum Tentriculorum (inierveniriadar septum) (see also Figs. 415, 417 and 

 418) separates the two ventricles from one another completely. It is nuiscidar in by far its 

 largest part (septum musculare ventriadornm) , is formed by a corresponding portion of the 

 musculature of each of the two ventricles and can be divided into its two components only by 

 artificial means. On contraction it thickens and the distance between the two sulci longi- 

 tudinales diminishes. The septum membranaceum ventriculorum (0. T. undefended space) is 

 a small area of pure connective tissue sitiuited just between and in front of the opposed margins 

 of the valvulae semilunarcs dextra et posterior aortae (see also Fig. 426); its right surface is 

 divided into two parts by the cuspis medialis valvulae tricuspidalis arising from it; the posterior 

 part looks xUto the right atrium, the anterior into the right ventricle. 



