The Muscular System 123 



muscle to bring about the contraction. Although this type of contrac- 

 tion never occurs in the living animal, it is important experimentally for 

 learning the details of muscular mechanics. The single muscle twitch 

 (Fig. 37) can be seen to consist of several different parts. 



>-^MUSCLe CLAMP 



>-*-MUSCLE LEVER 



BATTERY 



Tr6"C"flr6"og'o~oyo 



KYMOGRAPH 



Fig. 36. — Diagram showing the setup for recording a simple muscle twitch. (From 

 Zoethout and Tuttle: Textbook of Physiology, The C. V. Mosby Company.) 



Fig. 37. — The cur\e of a single muscle twitch recorded by a kymograph. A, 

 Stimulus applied; B, beginning of contraction, C to D, relaxation; time in 1/100 

 second. (From Zoethout and Tuttle: Textbook of Physiology.) 



