282 



HUMAN PHYSIOLOGY 



different in the case of the upper from what it is with 

 the lower ribs. We will consider first the effect of raising 

 the upper ribs upon the thoracic cavity. 



The first rib is a short one, curving with a small 

 radius from its attachment to the first dorsal vertebra 



FIG. 62. Above, the first and second ribs are viewed from the right. 

 To elevate them is to carry forward their ventral ends and the breast 

 bone, deepening the chest. 



Below, the ninth and tenth ribs are viewed from behind. As they 

 are raised the chief result is a lateral spreading. 



to reach the upper end of the breast bone. The ventral 

 ends of the first ribs are considerably below the dorsal 

 as observed on the erect figure. Their axis of rotation 

 is around a line drawn from right to left across the 



