XVI . CONTENTS. 



CHAPTER XVIII. 



THE MECHANISM OF RESPIRATION. 



PAGE 



Gas Interchange, 323 



Structure of the Lungs and Air Passages, 326 



The Thorax, 329 



Thoracic Movements, 330 



Inspiratory Muscles, 333 



Expiration, 337 



Function of the Pleura, 338 



Pressure Differences in the Air, 340 



The Volume of Air, 341 



Nervous Mechanism of Respiration, 344 



Modified Respiratory Movements, 349 



CHAPTER XIX. 



THE CHEMISTRY OF RESPIRATION. 



Composition of the Atmosphere, 351 



Expired Air, 352 



Changes the Blood undergoes in the Lungs, 354 



Gases in the Blood, 355 



Internal Respiration, . 359 



Respiration of Poisonous Gases, 360 



Ventilation, 360 



Asphyxia, 362 



CHAPTER XX. 



BLOOD-ELABORATING GLANDS. 



Ductless Glands, 365 



Suprarenal Capsule, . . ' 366 



Thyroid Body, 366 



Thymus, 366 



Spleen, 367 



Functions of the Spleen, 371 



Glycogenic Function of the Liver, 373 



Glycogen, 375 



