142 



THE MUSCLE CELLS 



The efficiency of this second phase of muscle work is less than 

 that of the contraction phase, which we saw was 91 per cent. 

 Taken together they give a gross efficiency 

 for a complete muscle twitch as 50 per cent. 

 But to this one might apply a correction to 

 take into account the energy expended 

 during muscle rest. 



(3) Rest. During complete inactivity, 

 energy is used for maintaining the muscle 

 FIG. 25. influence of the in a state of preparedness for action, just 



length of a muscle upon the _ . i i *_ 



work done. A muscle one as a nation has to spend money maintam- 



inch long (left-hand figure) 

 in contracting to half its 

 length lifts a weight to half 

 an inch. A muscle of two 

 Inches, on the other hand, is 

 capable of lifting the weight 

 to one inch. 



(Noel Paton's Essentials of erroneously termed rest. As we shall see in 

 the sequel, this phase is anything but restful. 

 Again, just as in peace time, the coordinating and integrating 

 machine of empire, the Cabinet, keeps our standing army in a 

 high state of efficiency, so the nervous system constantly sends 

 impulses to the muscles, keeping them ready for instant action. 

 This state of resting readiness may be called the tone of muscle, 

 and is, as indicated above, regulated in part by the nervous 

 system (q.v.). During rest, energy is expended which if sub- 

 tracted from the total energy expended during restitution would 

 raise the efficiency of that phase by about four per cent. 



ing an army in peace time, so the muscle 

 cell must always be ready for action. This 

 is the third phase of muscular life 



TABLE XXIII. 



OXYGEN USED BY CAT'S Gastrocnemius M. (VERzAR, 1912). 



