HYGIENE OF RESPIRATION 



I6 7 



removed by breathing, but if the lungs are contracted by 

 strong and long expirations, more air from deep down in 

 the lungs, and therefore fouler air, is removed. When the 

 lungs expand fully, their surface is increased and every 

 little air cell is opened, helping the exchange of carbon 

 dioxid and oxygen through the thin walls. 



278. You have just been studying about the three 

 methods of breathing according as you use (i) the inspira- 



FiG. 143. 



FIG. 144. 



FIG. 145. 



Diagrams illustrating Proper and Improper Methods of Breathing. 



Dotted lines show area of expansion. 



Fig. 143. Female figure encased in corset. Expansion at the waist is here impossible 

 and the breathing is called " collar bone breathing." 



Fig. 144. Male figure. Here, owing to pressure of clothing and faulty position, expan- 

 sion of chest is impeded and breath is taken by the " diaphragmatic method." 



Fig. 145. Figure properly poised and free from constriction. Here the entire thorax 

 can move freely and normal breathing is the result. 



tory muscles, (2) the expiratory muscles, (3) both. The 

 breathing may be varied also by the activity of the muscles 

 prominent in (i) the abdomen, (2) the chest, (3) both. 

 This gives rise to 



279. Abdominal Breathing, Chest Breathing, and Full 

 Breathing. See whether you can make waist, chest, and 

 abdomen expand at the same time. See whether you can 

 make waist, chest, and abdomen contract at the same time. 



