Active Hyperemia. 



395 



that when a muscle is exerting its maximum effort and there is no alternation 

 of contraction between groups of muscle-fibres, to sustain the effort for a 

 considerable time involves the working of the muscle in the complete 

 absence of fresh blood ; in addition to the possible production of metabolites 

 of activity we have here to consider the development of asphyxial products. 

 This is a point of great importance in physical culture, e.g., the maintenance 

 of a continued position like " attention." The phenomenon is seen in its 

 most exaggerated form in muscular " cramp." 







Myogram 







1 ! 1 II 1 1 1 1 1 1 III 1 1 1 1 1 1 i 1 1 1 1 



_ : — . •• 1 ; ■ 





z" 





Fig. 11. 



Ischcemia : The vaso-dilator effect of asphyxial products may be seen by 

 placing artery forceps on the lingual arteries (fig. 12); on releasing the 

 forceps the tongue dilates to an extent greater than in the resting condition 

 and pulsation becomes more marked. This result confirms the findings of 

 Anrep (1912) for the fore-limb. 



Tg. vol. 



. '■ . On . m 

 1 min. :i 



Off 



Lingual art § 

 clipped 



Fig. 12. 



Venous Congestion : Compression of the lingual vein leads to venous engorge- 

 ment of the tongue ; on releasing the clip the venules quickly empty but the 



