376 ADVANCED PHYSIOLOGY 



apart, and are adequate for the kind of work being done. 

 If one feels faint or nauseated before a meal, the probability 

 is that his last meal was deficient and a lunch would have been 

 very wisely taken. The stomach, digestive organs and glands 

 must be given rest, just as we know muscles and nerves 

 demand it. The appetite may suggest irregular and frequent 

 eating, but its suggestions may not always be followed. See 

 page 51. 



Alcoholic Beverage s. The effect of alcoholic beverages 

 upon the nervous system has already been discussed. 



Exercise. Muscles comprise fully 40 %of the body weight, 

 and their condition, healthful or otherwise, affects the body 

 as a whole. The blood, going to and from every tissue, 

 carries away materials from muscle of a nature unlike that 

 taken from any other part of the body. As the blood stream 

 hurries on, every other tissue, e. g. nerves, glands, etc., is 

 influenced by what has gone into the blood stream from 

 muscles. 



These changes which take place when a resting muscle 

 begins to act are as follows: (a) Sarco-lactic acid is produced 

 and replaces the alkaline character of resting muscle, (b) 

 Loosely combined oxygen is speedily associated with carbon 

 forming CO 2 . (c) Glycogen already stored in the muscle is 

 transformed and poured into the blood as dextrose, (d) The 

 temperature of the muscle is raised. 



These changes, happening in the muscle itself, are, through 

 the blood stream, felt throughout the body, with many accom- 

 panying results, some of which are: (a) The respiration is 

 quickened and as a result the air is rapidly changed in the 

 lung recesses and the respiratory muscles are exercised and 

 given new "tone." (b) The heart beats faster, all blood tubes 

 are thus flushed and their own muscular walls called into 

 action, (c) The mechanism which regulates the temperature 

 of the whole body is roused and put to work, (d) Blood and 

 lymph are forced away from points where they may have 



