THE MUTUAL HELP OF DIFFERENT ORGANS. IQI 



course come to your nnind at once. There are others 

 that you may think of, as you have also learned that 

 when you exercise your muscles, the heart and lungs 

 work more vigorously to supply them with sufficient 

 nourishment and oxygen, and to carry off their extra 

 wastes; that when the air is cold, the blood-vessels of 

 the skin contract and drive blood away from the surface 

 to prevent too rapid cooling (p. 178); that when your 

 body is hot, the sweat-glands become very active so as to 

 cool the blood, and through it the internal organs(p. 67); 

 that when partly digested food passes from the stomach 

 into the small intestine, the gall-bladder at once squeezes 

 out bile (p. n6)tobe mixed with it, and help the intes- 

 tine in digestion and absorption. 



All of the things above mentioned are done without 

 our will, and some of them even without our being 

 aware when they take place, as the pouring of bile into 

 the small intestine. They are but a few examples out 

 of hundreds, which show that our organs work together 

 for the good of the whole body, and often help one an- 

 other without our planning it, or our minds having any- 

 thing to do with it. Very clearly there must be some 

 means by which the various organs are made to work in 

 such harmony. 



3. The Nervous System. When we try to imagine how 

 each organ might be put in communication with all the 

 others, probably the first idea that comes to mind is that 



2. Of what is coughing an example ? How do the heart and lungs 

 help the muscles during exercise ? How do the blood-Tessels of the 

 skin keep the rest of the body from being too much cooled ? How do 

 the sweat-glands aid the rest of the body ? How does the gall-bladder 

 aid the small intestine in digesting? In what way are the above ac- 

 tions performed? What do these few examples show? 



3. In thinking of communication between the organs, what idea 



