8o 



HUMAN BIOLOGY 



above. 2. There are three pairs of - 



none above, but all ribs of the upper chest are 



ribs below, while there are 

 ribs. 3. The 



lower of the joints between the seven pairs of true ribs and the sternum 



are more flexible than the upper joints because . (Observe the 



joints in Fig. 75.) 4. The walls of the waist swing - -and , 



while the walls of the upper chest must move - - and - . 5. The 

 bones of the - - rest upon the upper chest. In upper chest breathing 



their weight, and the weight of both of the 

 lifted. (Fig. 28.) Test by trying it. 



must, therefore, be 



Hygienic Habits of Breathing. - - Chest breathing uses 

 chest chiefly, abdominal breathing uses abdomen chiefly, 



FIG. 77. FIG. 78. FIG. 79. 



FIG. 77. FEMALE FIGURE ENCASED IN CORSET. Expansion at the waist is here impossi- 

 ble and the breathing is called " collar-bone breathing." 



FIG. 78. MALE FIGURE. Here, owing to pressure of clothing and faulty position, expan- 

 sion of chest is hindered and breath is taken by the " abdominal method." 



FIG. 79. FIGURE PROPERLY POISED AND FREE. Here the entire thorax can move freely, 

 and natural breathing is the result. (For blackboard.) From Latson. 



full breathing uses both. These three forms depend 

 upon whether the breathing is carried on by using 

 the muscles of (i) the chest, (2) the abdomen, or (3) both 

 (see Figs. 77, 78, 79). There has been much debate 

 among physicians, surgeons, and singers as to which of 

 these methods is best. Probably this question would not 

 have been raised but for the confining and deforming 

 effect of clothing upon the waist. Full breathing is used 



