86 



EIGHTH LECTURE. 





^^: 



Fig. 82. — Muscular filaments of the 

 heart. To the right appear transparent 

 boundaries and nuclei. 



The remaining transversely striated muscles show the fila- 

 ments arranged parallel, slightly prismatically flattened against 



each other (Fig. 83, a), and in 

 man containing the muscular cor- 

 puscles \e) in their periphery. 

 Between them occurs a scanty 

 amount of connective tissue, the 

 highway for vessels {d) and nerves. 

 With rich living this may develop 

 fat cells (Fig. 50). 



A varying number of muscu- 

 lar fibres unite into bundles, 

 measuring 0.5 to 1 mm., which are 

 separated from the neighborhood 

 by abundant connective tissue. 

 Such primary bundles then unite 

 into secondary ones. The con- 

 nective tissue covering of the 

 muscle bears the name of peri- 

 mysium externum, in contradistinction to the perimysium 

 internum of the inner connecting substance between the fila- 

 ments and bundles. 



Smooth muscles also show a 

 bundle-like grouping. 



We come, finally, to the con- 

 nection with the tendons. The 

 latter tissue has already been de- 

 scribed above, page 57. 



With a rectilinear insertion 

 (Fig. 75) the sarcous substance (a) 

 appeared to pass immediately 

 over into the tendinous bundle 

 [b) ; not so, however, with an 

 oblique insertion, where an inter- 

 rupted muscular end becomes ap- 

 parent. 

 Weismann first obtained convincing appearances here by 



Fig. 83. — Transverse section through 

 the human biceps brachii ; «, the muscu- 

 lar fibres ; />, section of a larger vessel ; 

 c, a fat cell lying in a large connective- 

 tissue interstice; d, capillaries cut across 

 in the thin connective-tissue layer be- 

 tween the several fibres; e, the nuclei 

 (muskelkorperchen) of the latter lying 

 on the sarcolemma. 



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