Xvi CONTENTS. 



CHAPTER XVIII. 



THE MECHANISM OF RESPIRATION. 



PAGE 



Gas Interchange, ........... 318 



Structure of the Lungs and Air-passages, ...... 321 



The Thorax, ........... 324 



Thoracic Movements, ... ..... . 326 



Inspiratory Muscles, ....;..-.. 329 



Expiration, ... ........ . 332 



Function of the Pleura, ... ...... 334 



Pressure Differences in the Air, ..... ... 336 



The Volume of Air, .......... 337 



Nervous Mechanism of Respiration, ....... 339 



Modified Respiratory Movements, ....... 345 



CHAPTER XIX. 



THE CHEMISTRY OF RESPIRATION. 



Composition of the Atmosphere, ........ 347 



Expired Air, ........... 348 



Changes the Blood undergoes in the Lungs, ..... 350 



Gases in the Blood, .......... 352 



Internal Respiration, .... ...... 355 



Respiration of Poisonous Gases, ........ 356 



Ventilation ........ . . . .357 



Asphyxia, ............ 358 



CHAPTER XX. 



BLOOD-ELABORATING GLANDS. 



Ductless Glands, ........... 361 



Supra-renal Capsule, .......... 362 



Thyroid Body, ........... 363 



Thymus, ............ 364 



Spli-en, ............ 364 



Functions of the Spleen, ......... 365 



Glycogenio Function of the Liver, ....... 369 



372 



