xiv CONTENTS. 



PAGE 



129. The cardiac impulse . . . 234 



130. The sounds of the heart 235 



Endocardiac Pressure. 



131. Methods of determining endocardiac pressure. Minimum and 

 maximum manometer. The negative pressure in the cardiac 



cavities 238 



132. Cardiac sound and tambour 240 



133. Discussion of cardiac curves 243 



134. The main events occurring in the ventricle during a beat . . 246 



135. The nature and causes of the negative pressure .... 247 



136. The duration of the several phases of the cardiac cycle . . . 249 



137. Summary of the events constituting a beat 251 



138. The work done 253 



SECTION IV. 

 THE PULSE. 



139. Methods of recording the pulse. The sphygmograph. The pulse 



curve 255 



140. Pulse tracing from an artificial model ; the features of the pulse 



wave . 257 



141. Characters of the pulse curve ; influence of pressure exerted by lever 260 



142. The changes undergone by the pulse wave along the arterial tract . 261 



143. The velocity of the pulse wave 262 



144. The length of the pulse wave 263 



145. Dicrotism. Secondary elevations. Katacrotic and anacrotic tracings 264 



146. The causes of the dicrotic wave 266 



147. The predicrotic wave 270 



148. Causes of anacrotic waves 271 



149. Venous pulse 271 



SECTION V. 

 THE REGULATION AND ADAPTATION OF THE VASCULAR MECHANISM. 



The Regulation of the Beat of the Heart. 



150. The two great regulators ; changes in the heart-beat and changes in 



the peripheral mechanism 273 



The Histology of the Heart. 



151. Cardiac muscular tissue. The structure of the frog's heart . . 274 



152. The structure of the mammalian heart 276 



153. The nerves of the heart. The ganglia of the heart .... 277 



The Development of the Normal Beat. 



154. Graphic record of the heart-beat. The beat of the frog's heart. 

 The sequence of events, and the descending scale of rhythmic 

 power 280 



