TABLE OF CONTENTS. 11 



SECTION V. 



PHYSIOLOGY OF THE ORGANS OF CIRCULATION OF THE 

 BLOOD AND LYMPH. 



PAGE 



CHAPTER XXV. THE VELOCITY AND PRESSURE OF THE BLOOD FLOW. . 434 



The Circulation as Seen Under the Microscope, 434. The Velocity of the 

 Blood Flow, 435. Mean Velocity in the Arteries, Veins, and Capillaries, 438. 

 Cause of the Variations in Velocity, 440. Variations of Velocity with the 

 Heart Beat or Changes in the Blood-vessels, 440. Time Necessary for a Com- 

 plete Circulation of the Blood, 441. The Pressure Relations in the Vascular 

 System, 442. Methods of Recording Blood-pressure, 442. Systolic, Dias- 

 tolic, and Mean Arterial Pressure, 446. Method of Measuring Systolic and 

 Diastolic Pressure in Animals, 447. Data as to the Mean Pressure in Arteries, 

 Veins, and Capillaries, 450. Methods of Determining Blood-pressure in the 

 Large Arteries of Man, 453. Normal Pressure in Man and Its Variations, 458. 



CHAPTER XXVI. THE PHYSICAL FACTORS CONCERNED IN THE PRO- 

 DUCTION OF BLOOD-PRESSURE AND BLOOD- VELOCITY 460 



Side Pressure and Velocity Pressure, 460. The Factors Concerned in Pro- 

 ducing Normal Pressure and Velocity, 463. General Conditions Influencing 

 Blood-pressure and Blood-velocity, 464. The Hydrostatic. Effect, 465. Ac- 

 cessory Factors Aiding the Circulation, 466. The C9nditions of Pressure 

 and Velocity in the Pulmonary Circulation, 467. Variations of Pressure in 

 the Pulmonary Circuit, 468. 



CHAPTER XXVII. THE PULSE 469 



General Statement, 469. Velocity of the Pulse Wave, 470. Form of the 

 Pulse Wave, Sphygmography, 472. Explanation of the Catacrotic Waves, 

 474. Anacrotic Waves, 475. The Kinds of Pulse in Health and Disease, 

 475. Venous Pulse, 475. 



CHAPTER XXVIII. THE HEART BEAT 477 



General Statement, 477. Musculature of the Auricles and Ventricles, 478. 

 Contraction Wave of the Heart, 479. The Electrical Variation, 480. Change 

 of Form during Systole, 481. The Apex Beat, 482. Cardiogram, 482. In- 

 traventricular Pressure during Systole, 484. The Heart Sounds, 485. Events 

 Occurring during a Cardiac Cycle, 488. Time Relations of Svstole and Dias- 

 tole, 489. Normal Capacity of Ventricle and Work Done by the Heart, 489. 

 Coronary Circulation during the Heart-beat, 491. Suction-pump Action of 

 the Heart, 492. Occlusion of the Coronary Vessels, 494. Fibrillar Contrac- 

 tions of Heart Muscle, 495. 



CHAPTER XXIX. THE CAUSE AND THE SEQUENCE OF THE HEART 



BEAT. PROPERTIES OF THE HEART MUSCLE 496 



General Statement, 496. The Neurogenic Theory of the Heart Beat, 497. 

 Myogenic Theory, 498. Automaticity of the Heart, 500. Action of Calcium, 

 Potassium, and Sodium Ions on the Heart, 501. Connection of Inorganic 

 Salts with the Causation of the Beat, 503. Maximal Contractions of the 

 Heart, 504. Refractory Period of the Heart Beat, 504. The Compensatory 

 Pause, 506. Normal Sequence of the Heart Beat, 507. Tonicity of the 

 Heart Muscle, 510. 



CHAPTER XXX. THE CARDIAC NERVES AND THEIR PHYSIOLOGICAL 



ACTION 512 



Course of the Cardiac Nerves, 512. Action of the Inhibitory Fibers, 512. 

 Analysis of the Inhibitory Action, 514. Effect of Vagus on the Auricle and 

 the Ventricle, 516. Escape from Inhibition, 517. Reflex Inhibition of the 

 Heart-beat, the Cardio-inhibitory Center, 517. The Tonic Activity of the 

 Cardio-inhibitory Center, 518. The Action of Drugs on the Inhibitory Ap- 

 paratus, 520. The Nature of Inhibition, 520. Course of the Accelerator 

 Fibers, 522. Action of the Accelerator Fibers, 523. Tonicity of the Accel- 

 erators and Reflex Acceleration, 524. The Accelerator Center, 525. 



CHAPTER XXXI. THE RATE OF THE HEART BEAT AND ITS VARIATIONS 



UNDER NORMAL CONDITIONS 526 



Variations in Rate with Sex, Size, and Age, 526. Variations Through the 

 Extrinsic Cardiac Nerves, 527. Variations with Blood-pressure, 527. With 

 Muscular Exercise, 528. With the Gases of the Blood, 529. With Tempera- 

 ture of the Blood, 529. 



