SYSTEMATIC SYNTHESIS OF TISSUES INTO ORGANS. 221 



349. THE STERNUM INCLINES outward at its lower 

 extremity when natural. 



350. A GENERAL VIEW OF THE FRAME OF THE CHEST 



SHOWS (see Fig. 4, PL 13), that its back part is compos- 

 ed of the dorsal portion of the Spinal Column, and a 

 portion of the ribs that curve backward before they ex- 

 tend along the sides of the chest, which they alone form, 

 in front it being formed of the ribs, their cartilages, and 

 the sternum. 



351. THE CHEST IN FORM is a double cone, the larg- 

 est circumference being about the middle of it. It is 

 flattened in front and also behind ; is shortest in front 

 and longest on the sides. 



352. THE CHEST is PARTIALLY DIVIDED into right 

 and left by the body of the spinal column, the front sur- 

 face of which is situated nearly one half the distance 

 from the surface of the backward curving ribs and the 

 sternum. 



353. THE FRAMEWORK OF THE CHEST is OPEN above, 

 where the opening is surrounded by the vertebras, ribs, 

 and sternum, and on the sides between and below the 

 ribs, where the opening is almost the full size of the 

 Chest. It has a singular outline, and is worthy of so 

 much study as shall make it familiar. 



354. THE CONSTRUCTION OF THE FRAME OF THE 

 CHEST, and the applicability of it, is most ingenious and 

 admirable. Its strength, from the arched form of the 

 ribs and the condensed air when the windpipe is closed, 

 is exceedingly great. The violence it can receive with- 

 out injury is astonishing. 



355. Illus. A loaded wagon passed over the chest of a man with- 

 out fracturing a rib. 



356. Being built upon the upper part of the spinal 



Column, THE CHEST IS PERFECTLY ADAPTED to be the SUp- 



port of the upper extremities, setting them out from the 



349. How does -? 360. What does ? 351. What -? 352. How -? 358. How 

 ? 354. What said of ? 355. Illustrate. 356. To what ? 



