MUSCULAK ARCHITECTURE OF THE HUMAN HEART 237 



/CLV 



Fig. 7 Posterior view, somewhat to the left, after the superficial sino-spiral 

 band has been removed to the posterior longitudinal sulcus. The deep bulbo- 

 spiral band, BS', enters the septum, above the superficial bulbo-spiral band, BS; 

 CLV, circular muscle band of the left venous ostium; TR, posterior triangular 

 field; IV, interventricular bands. 



