xii PHYSIOLOGY 



PAG) 



plethysmograms representing pulsatory oscillations in tin- volume of the 

 arteries. 12. Sehema of meehaiileal conditions of the circulation in the 

 three great vascular sy.^tems ; determination of duration of the entire 

 circulation. Bibliography. 



CHAPTER IX 



PHYSIOLOGY OF CARDIAC MUSCLE AND NERVES . 285 



1. Intrinsic processes by which cardiac rhythm is determined and 

 regulated. 2. Extrinsic chemical conditions of cardiac activity. 3. 

 Effects of ligation and section on different parts of the heart. 4. 

 Automatic or reflex activity of heart. 5. Myogenic or neurogenic 

 origin of cardiac rhythm. 6. Evidence for these conflicting theories. 



7. Special mode in which cardiac muscle reacts to external stimuli. 



8. Regulation of cardiac rhythm by nervous system ; inhibitory or 

 diastolic nerves. 9. Accelerator or systolic nerves. 10. Theory of 

 anabolic action of diastolic nerves and katabolic action of systolic 

 nerves. 11. Afferent nerves of heart or other parts of the body, which 

 influence cardiac rhythm. 12. Nerve centres for cardiac nerves ; 

 their tonic excitability, and theory of regulation of cardiac rhythm. 

 Bibliography. 



CHAPTER X 



PHYSIOLOGY OF VASCULAR MUSCLE AND NERVES . . 341 



1. Discovery of vasomotor nerves. 2. Vascular tone and its 

 rhythmic and a-rhythmical variations, as depending essentially upon 

 the automatic and reflex excitability of the .smooth muscle cells. 3. 

 Theory of vaso-constrictor nerves. 4. Theory of vaso-dilator nerves. 

 5. Vascular reflexes. 6. Bulbar vaso-constrictor centre. 7. Spinal 

 and cerebral centres for vaso-constrictor nerves. 8. Centres for vaso- 

 dilator nerves. Bibliography. 



CHAPTER XI 



CHEMISTRY AND PHYSICS OF RESPIRATORY EXCHANGES . 369 



1. Early notions of the importance of respiration (Aristotle, Galen, 

 Leonardo da Vinci, van Hclmont, Boyle, Hook, Fracassati, Lower, 

 Mayow). 2. Modern doctrines (Black, Bergmann, Priestley, Lavoisier). 

 3. Theory of gas exchanges in the lungs and tissues (Lagrange and 

 Spallanzani, W. Edwards). 4. Extraction of gases from the blood 

 (Magnus. L. Meyer, Hoppe - Seyler, Ludwig, Pfliiger). 5. A^arying 

 content of arterial, venous, and asphyxiated blood. 6. State of the 

 oxygen in the blood. 7. State of the carbonic acid in the blood. 8. 

 Tension of gases in venous and arterial blood and in inspired and ex- 

 pired air ; theory of pulmonary gas exchange by diffusion and by 

 secretory processes. 9. Theory of gas exchanges in the tissues. 10. 

 The respiratory quotient and its variations. Bibliography. 



