HYGIENE OF BLOOD AND CIRCULATION 191 



A weak heart usually shows itself in breathlessness. If you 

 cannot climb stairs, or take a brisk walk, or play a lively 

 game, without getting out of breath, the trouble is more likely 

 with your heart than with your lungs. In training for athletics 

 one of the most important things is to acquire ^'wind," that is, 

 the ability to continue severe exertions without losing breath. 

 This is in fact a training of the heart, as well as a training in 

 correct breathing habits. Under suitable directions one can 

 strengthen his heart considerably by means of graded exer- 

 cises in walking-, running, climbing, etc. Indeed, there is the 

 possibility of overdeveloping the heart. But giving the heart 

 occasional severe strain is not the same as training it for hard 

 work. A person with a weak heart should not be engaged in 

 work that strains this organ severely. 



HYGIENE OF THE BLOOD AND THE CIRCULATION 



1. The relation of the blood to the health of the body 



SuppHes tissues with needed materials from outside 



Water ; food ; oxygen 

 Removes wastes from living cells ; removes broken-down (dead) 



parts ; removes foreign particles 

 Distributes materials produced in special parts (hormones) 

 Counteracts foreign substances 



2. The relation of different organs and organ systems to the healthy 



condition and effectiveness of the blood 

 Food system Hormone system 



Breathing system (Nervous system) 



(Excretion system) 



3. The pulse and sounds of the heart 



Cause of pulse 



Character of pulse under different conditions 



Meaning of pulse characteristics : soft ; irregular 



How '' leaky heart " is recognized 



Meaning of leaky heart 



4. Treatment of bleeding 



Cuts and wounds Nosebleed 



From arteries How to stop bleeding 



From veins Precautions against infection 



