CONTENTS. XV 



PAGE 



The Cause of Coagulation, 252 



^Coagulation in the Vessels, 253 



Formation of Fibrin, 254 



CHAPTER XVI. 



THE HEART. 



Pulmonary and Systemic Circulations, 257 



x'Method of the Circulation of the Blood, 259 



The Heart, 262 



Arrangement of Muscle Fibres, 262 



Minute Structure of the Heart, 264 



^Action of the Valves, 266 



Movements of the Heart, 268 



v-Cycle of the Heart Beat, , 269 



The Heart's Impulse, 272 



Heart Sounds, 274 



Innervation of the Heart, 277 



Local Centres, 277 



^ Inhibitory Nerves, 282 



Acceleration Nerves, 283 



Afferent Cardiac Nervts, 284 



CHAPTER XVII. 



THE BLOOD VESSELS. 



Structure of the Vessels, 285 



The Capillaries, 287 



Relative Capacity of the Vessels, 289 



Physical Forces of the Circulation 291 



Blood Pressure, 293 



Measurement of Blood Pressure, 297 



Variations in the Blood Pressure, 301 



Influence of Respiration on the Blood Pressure, 303 



The Arterial Pulse, 308 



Methods of Obtaining Puise Tracings, 309 



Variations in the Pulse, 313 



Velocity of the Blood Current, 313 



Controlling Mechanisms of the Blood Vessels, 317 



