144 ELEMENTS OF PHYSIOLOGY 



11. Why should a youth who wishes to excel in athletic contests 

 abstain from the use of tobacco ? 



12. What order of lever is the foot when a weight is lifted on the 

 toes (Fig. 1 19) ? What order of lever do we use when we lift the leg 

 while sitting down ? 



13. Locate the three points of a lever when swinging the arm from 

 the shoulder ; when bending a finger ; when tapping the ground with 

 the toes (Fig. 117) ; when using the foot in walking (Fig. 118). 



14. Why can we raise a heavier weight with the hand when lifting 

 from the elbow than from the shoulder? (See Elementary Physics.) 



15. Which bone is chiefly in motion when we are using a gimlet? 



1 6. Why does using a muscle cause fatigue ? 



17. Why can we chew harder with the back teeth than the front 

 ones? (See Physics.) 



1 8. Why is it an advantage that the heel bone projects? That the 

 bones of the limbs are enlarged at the joints? 



APPLIED PHYSIOLOGY 

 EXERCISE I 



1. Does a few minutes 1 practice in a gymnasium suffice for a day's 

 exercise ? 



2. Is there any relation between the amount of bodily exertion 

 necessary for a person's health and the amount of wealth he possesses? 



3. It is said that an Indian often runs or trots sixty miles per day, 

 and that he rests his muscles without stopping by running for a 

 while chiefly with the hip joint and muscles of the thigh, then with the 

 knee joint and muscles of the upper leg. Can you rest some of the 

 running muscles while running? 



4. Can you relax the chewing muscles so that the lower jaw will 

 swing loosely when the head is shaken? 



5. Can you relax the muscles of the forearm so that the hand will 

 shake loosely on the wrist and the fingers in their sockets ? 



6. Can you relax the whole arm so that another person can move it 

 as a flexible rope ? 



7. Which joints of the limbs lock and refuse to bend further when 

 the limb is straightened? 



8. Which muscles have become useless with most persons, al- 

 though some can still use them (Fig. 122)? 



9. The average man has 60 Ibs. of muscle and 2 Ibs. of brain : one 

 half of the blood goes through the muscles and one fifth goes through 



