xvi CONTENTS 



CHAPTER XXIII 



RESPIRATION. THE MECHANISM OF BREATHING. THE REGULATION OF 



BREATHING 



PAGE 



Definitions. Respiratory organs. Air-passages and lungs. Trachea 

 and bronchi. Structure of lungs. Pleura. Respiratory movements. 

 Anatomy of thorax. Changes in size of thorax. Forced respiration. Res- 

 piratory sounds. Capacity of lungs. Aspiration of thorax. Respiratory 

 center. Excitation of respiratory center. Sensitiveness of respiratory 

 center. Eupnea, hyperpnea, dyspnea, apnea. Holding the breath. As- 

 phyxia. Artificial respiration. Modified respiratory movements 386 



CHAPTER XXIV 



RESPIRATION. THE GASEOUS INTERCHANGES 



Nature of the problems. Changes produced in air by being breathed. 

 Ventilation. Changes undergone by blood in lungs. Blood gases. Laws 

 governing absorption of gases by liquid. Absorption of oxygen by blood. 

 Oxygen interchanges in blood. Carbon dioxid in blood. Hormone action 

 of carbon dioxid. Tissue respiration. Respiratory changes in muscular 

 exercise. Coal gas poisoning 410 



CHAPTER XXV 



FOODS! THEIR CLASSIFICATION 



What constitutes food. Function of food. Classes of foods. Occur- 

 rence of nutrients in food. Inorganic essential accessories. Organic essen- 

 tial accessories. Vitamines. Occurrence of occasional accessories in food. 

 Nutrients. Mixed foods. Flesh. Eggs. Milk. Vegetable foods. Com- 

 position of foods. Alcohol. Tea, coffee, cocoa. Food poisoning 428 



CHAPTER XXVI 



THE ALIMENTARY CANAL AND ITS APPENDAGES 



General arrangement. Subdivisions of the canal. Mouth. Teeth. 

 Tongue. Salivary glands. Pharynx. Esophagus. Stomach. Small in- 

 testine. Large intestine. Nerves of intestines. Liver. Pancreas. Blood- 

 vessels of canal 442 



CHAPTER XXVIII 



THE CHEMISTRY OF DIGESTION 



Object of digestion. Nature of the digestive process. Digestion prod- 

 ucts. Saliva. Gastric juice. Pancreatic juice. Bile. Succus entericus. 

 Summary of digestive process. Bacterial digestion. Prevention of self- 

 digestion 462 



