2 4 



THORAX 



introduce one hand into each pleura, and placing an index 

 ringer in each apex, he should note that the apex is situated 

 about one inch above the medial third of the clavicle, a fact 

 which he can demonstrate with the aid of his partner on the 

 opposite side, who should hold two macerated clavicles in their 

 proper positions. The apices of opposite sides, therefore, are 

 some distance apart, and are separated from each other by the 



structures occupying 

 the median part of the 

 neck ; i.e. the trachea, 

 the oesophagus, and 

 the great vessels pass- 

 ing to and from the 

 head. As the anterior 

 margins of the pleurae 

 are traced downwards 

 from the apices they 

 will be found to con- 

 verge, passing behind 

 the sterno - clavicular 

 joints and coming into 

 apposition at the lower 

 border of the manu- 

 brium, immediately to 

 the left of the median 

 plane. Traced further 

 downwards, the an- 

 terior margins remain 

 in apposition, the right 

 FIG. 7. Diagram to show the relation of the often Overlapping the 

 lungs and the pleural sacs to the anterior left and both i nc li n i ng 

 thoracic wall. The lungs are depicted in .. , . , . f 



red, and the pleural sacs in blue. Slightly to the lett, as 



far as the level of the* 



fourth costal cartilages. From the fourth cartilage the 

 anterior margin of the right sac continues to descend, still 

 with a slight inclination to the left, till it reaches the xiphoid 

 process, where it becomes continuous with the inferior margin. 

 The inferior margin turns laterally, passing behind the xiphoid 

 process and the cartilage of the seventh rib ; it then crosses 

 the junction of the bone and cartilage of the eighth rib, 

 and reaches the level of the tenth rib in the mid-axillary 

 line; turning posteriorly, it crosses the eleventh and twelfth 



