CONTENTS. xiii 



PAGE 



107. The structure of capillaries; epithelioid cells. The size of capillaries 



and variations in their calibre 190 



108. The structure of minute arteries 193 



109. The structure of larger arteries ....... 194 



110. The structure of the veins 196 



111. Some points in the structure of the heart 197 



112. The main features of the vascular apparatus 198 



SECTION II. 

 THE MAIN FACTS OF THE CIRCULATION. 



113. Behaviour of arteries contrasted with that of veins .... 201 



114. Blood-pressure in an artery and in a vein 202 



115. Methods of registering blood-pressure; mercurial manometer. Ky- 

 mograph. The blood-pressure curve 204 



116. Characters of the blood-pressure in various arteries and veins. 

 Blood-pressure in the capillaries. Fall of blood-pressure in the 

 minute vessels .......... 207 



117. The circulation through the capillaries, and small vessels. Peripheral 



resistance 209 



Hydraulic Principles of the Circulation. 



118. The three main physical facts of the circulation; the central pump, 



the peripheral resistance and the elastic tubing . . . 211 



119. The conversion of the intermittent into a continuous flow by means 



of the elastic reaction of the arteries ...... 212 



120. Artificial Model. Arterial and venous pressure with great and with 



little peripheral resistance ....... 214 



121. Additional aids to the circulation in the living body . . . 219 



Circumstances determining the Rate of the Flow. 



122. Methods of determining the rate of the flow. Hsemadromometer, 

 Eheometer, Haernatachometer. The rate of flow in arteries, 



veins and capillaries 220 



123. The rate of flow dependent on the width of the bed . . . . 223 



124. The time of the entire circuit 225 



125. Summary of the main physical facts of the circulation . . . 226 



SECTION III. 

 THE HEART. 



The Phenomena of the Normal Beat. 



126. The visible movements 228 



127. The cardiac cycle ; the series of events constituting a beat . . 229 

 128. The change of form 232 



