48 



PHYSIOLOGY. 



TABLE OF FUNCTIONS. 

 3RGANIC. ANIMAL, OR OF RELATION. 



1. Digestion. 1. Sensation. 



2. Absorption. 2. Muscular motion. 



3. Respiration. 3. Menial manifestation. 

 Nutritive. ^ 4. Circulation. 



5. Nutrition. ; 



6. Secretion. V / . ; 



7. Calorification. 



Reproductive. < 8. Generation. 



Three of these have been called the vital functions, viz., inner- 

 vation, circulation, and respiration; these constitute the vital tripod, 

 the maintenance of which, is essential to life. 



ORGANIC FUNCTIONS. 



DIGESTION, 



The first of the organic functions maybe defined as that by which 

 the food or aliment is " reduced to such a condition that the nutri- 

 tive 'material can he separated from itP In animals, the food being 

 for the most part in a solid form, requires to be brought to a fluid 

 state before it can be inservient to nutrition, hence the necessity for 

 a digestive process. 



In the animal body, aliment is demanded for four different pur- 

 poses. First, for the original construction or building up of the 

 organism. (Seco^i<i, to supply the loss occasioned by the continual 

 decay, even when in repose. Third, to compensate for the waste 

 occasioned by the active exercise of the nervous and muscular sys- 

 tems. Fourth, to supply the materials for the heat-producing pro- 

 cess, by which the temperature of the body is kept up. 



The amount required for these several purposes, varies according 

 to the condition of the body as regards exercise or repose, external 

 heat and cold, and the age of the individual, a larger quantity being 

 demanded in youth in proportion to the size of the body, than in 

 manhood. Any drain upon the system also increases the demand. 



There can be no universal law laid down as to the amount re- 

 quired, so much depending. upon the external conditions in which the 

 individual may be placed. The diet scale in the British navy allows 

 to each man from 31 to 35i ounces of dry nutritious matter daily ; 

 of this 26 oz. are vegetable, and the rest animal, 9 oz. of salt meat, 

 or 4-2- of fresh meat, being the allowance of the latter. A mixed diet 

 seems to be absolutely indispensable, where such a variety of tissues 

 have to be repaired. The disastrous effects resulting from the long- 

 continued use of one kind of food, are to be attributed not so much 



