CHAPTER I 



GENERAL PHYSIOLOGY OF MUSCLE 



CONTENTS. 1. Skeletal muscles; excitability and the conditions which 

 regulate it. 2. Curves of muscular contraction. 3. Theory of contraction in 

 tetanus ; the muscle sound. 4. Propagation of excitatory wave along the muscle 

 on exciting with induced or constant currents. 5. Minute structure of striated 

 muscle fibres ; changes during contraction. 6. Muscular tone, contracture, and 

 capacity of muscle for active elongation. 7. Chemical composition of muscle in 

 rest and activity. 8. Metabolism in muscle and sources of the energy developed. 

 9. Muscular work and muscular energy. 10. Heat production in muscle. 

 11. Electrical changes during rest and activity. 12. Origin of muscular activity. 

 Bibliography. 



FROM the physiological standpoint the higher animal organism 

 may be treated as a system of blood-forming organs, at the service 

 of a sensory-motor system. The first of these the vegetative or 

 involuntary system subserves the internal life of the body, and 

 its function is to prepare and keep approximately constant the 

 mass and constituents of the blood and lymph which provide the 

 common nutriment : the second the organic or voluntary system 

 subserves the phenomena of external life, and maintains and regu- 

 lates the relations between the organism and its environment. 



But this distinction, proposed by Xavier Bichat, has little 

 intrinsic value, however useful it may be in the classification of 

 functions. The two systems do not constitute two separate 

 organisms, like the two primitive layers of the blastoderm, but 

 form a single complex indivisible organism, in which the specific 

 functions of both systems are sharply differentiated and localised. 

 Bones, tendons, and other forms of connective tissue participate 

 in the structure of the organs and mechanisms of animal life, and 

 although they remain passive during the activity of the muscles 

 and nervous system they make the functions of the latter possible, 

 and are thus important constituents of the sensory-motor system. 

 On the other hand motor and sensory elements contribute to 

 the structure of the organs and systems of vegetative life ; among 

 the former are amoeboid cells, ciliated epithelia and muscle 

 fibres, among the latter not only the nerve plexuses of the 

 VOL. in 1 B 



