CONTENTS xiii 



PART III 

 CIRCULATION OF THE BLOOD 



CHAPTER XV PAGE 



BLOOD PRESSURE 122 



The Mean Arterial Blood Pressure, 123; Mercury Manometer Tracings, 123; 

 Spring Manometer Tracings, 12(5; Clinical Measurements, 128. 



CHAPTER XVI 



THE FACTORS CONCERNED IN MAINTAINING THE BLOOD PRESSURE 134 



Pumping Action of the Heart, 134; Peripheral Resistance, 134; Amount of 

 Blood in the Body, 135; Effects of Hemorrhage and Transfusion, 139; Viscos- 

 ity of the Blood, 140; Elasticity of Vessel "Walls, 142. 



CHAPTER XVII 



THE ACTION OF THE HEART 144 



The Pumping Action of the Heart, 144 ; Intracardiac Pressure Curves, 146 ; 

 Comparison of the Curves, 148. 



CHAPTER XVIII 



THE PUMPING ACTION OF THE HEART (CONT'D) 151 



Contour of the Intracardial Pressure Curves, 151 ; Ventricular Curve, 151 ; 

 Auricular Curve, 153; The Mechanism of Opening and Closing of the Valves, 

 154; The Heart Sounds, 157: Causes of Sounds, 157; Records of Sounds 

 (Electrophonograms) , 1 58. 



CHAPTER XIX 



THE NUTRITION OF THE HEART 161 



B-lood Supply, 161; Perfusion of the Heart Outside the Body, 161; Resuscita- 

 tion'of the Heart in Situ, 164; Relationship of the Chemical Composition of the 

 Perfusion Fluid in Cold-blooded and Warm-blooded Hearts, 165. 



CHAPTER XX 



PHYSIOLOGY OF THE HEARTBEAT 170 



Origin and Propagation of the Beat, 170; Myogenic Hypothesis, 171; Neuro- 

 genic Hypothesis, 172; The Pacemaker of the Heart and Heart-block, 174; 

 Physiologic Characteristics of Cardiac Muscle, 176. 



CHAPTER XXI 



PHYSIOLOGY OF THE HEARTBEAT (CONT'D) 182 



Origin and Propagation of the Beat in the Mammalian Heart, 182 ; Conduct- 

 ing Tissue in the Mammalian Heart, 182; Site of Origin of Beat, 187. 



CHAPTER XXII 



PHYSIOLOGY OF THE HEARTBEAT (CONT'D) 101 



Alode of Propagation of the Beat in the Auricles ami from the Auricles to the 

 Ventricles, 191 ; Spread of Beat in the Ventricle, 193 ; Fibrillation of the Ven- 

 tricles ami Auricles, 195. 



