J ATOMY A\ 



JRFACE 





On the left side, beginning at the sternoclavicular articulation, it reaches the 

 midpoint of the junction between the manubrium and body of the sternum, and 

 extends down the midsternal line in contact with that of the opposite side to the 

 level of the fourth costal cartilage. It then diverges lateralward and is continued 

 downward slightly lateral to the sternal border, as far as the sixth costal cartilage. 

 Running downward and lateralward from this point it crosses the seventh costal 

 cartilage, and from this onward it is similar to the line on the right side, but at a 

 slightly lower level. 



Lungs (Figs. 1216, 1217). The apex of the lung is situated in the neck above the 

 medial third of the clavicle. The height to which it rises above the clavicle varies 

 very considerably, but is generally about 2.5 cm. It may, however, extend as 

 high as 4 or 5 cm., or, on the other hand, may scarcely project above the level 

 of this bone. 



Flo. 1217. Side of thorax, showing surface markings for bones, lungs (purple), pleura (blue), and spleen (green). 



In order to mark out the anterior borders of the lungs a line is drawn from each 

 apex point 2.5 cm. above the clavicle and rather nearer the anterior than the 

 posterior border of Sternocleidomastoideus downward and medialward across the 

 sternoclavicular articulation and manubrium sterni until it meets, or almost meets, 

 its fellow of the other side at the midpoint of the junction between the manubrium 

 and body of the sternum. From this point the two lines run downward, prac- 

 tically along the midsternal line, as far as the level of the fourth costal cartilages. 

 The continuation of the anterior border of the right lung is marked by a prolonga- 

 tion of its line vertically downward to the level of the sixth costal cartilage, and 

 then it turns lateralward and downward. The line on the left side curves lateralward 

 and downward across the fourth sternocostal articulation to reach the parasternal 

 line at the fifth costal cartilage, and then turns medialward and downward to the 

 sixth sternocostal articulation. 



