148 HUMAN PHYSIOLOGY CHAP, xi 



3. The fats and sugars are oxidized and produce heat. 

 Their wastes are carbon dioxid and water. 



4. Water and salt are not changed in the cells but are im- 

 portant in building up and repairing and in stimulating the 

 cells to activity. 



5. Carbon dioxid, ammonia compounds, and all other 

 waste materials formed in the cells are given off to the lymph. 



6. The carbon dioxid enters the blood capillaries and is 

 carried to the lungs, where it is selected out of the blood and 

 exhaled from the body. 



7. The other wastes are drained off through the lymphatics 

 which finally empty into the subclavian veins near the base of 

 the neck. 



8. The liver, pancreas, thyroid bodies, adrenals, lymph 

 nodes, and perhaps the spleen are active in producing impor- 

 tant changes in the blood as it circulates through them. 



9. The useless proteid products are changed to urea in the 

 liver and thrown back into the circulation. 



10. The oxidation of foods in all cells of the body produces 

 a large amount of heat that is used to maintain the body tem- 

 perature at 981 F. and to furnish energy. Friction produces 

 a small amount of heat. 



11. The heat is lost by (i) radiation from the skin, (2) the 

 escape of watery vapor from the lungs and skin, and (3) the 

 excretion of material from the kidneys and bowels. 



12. There are nerves which regulate the production and the 

 loss of heat. 



