THORACIC CAVITY 



lung. The lung, thus set free, is to be removed from the 

 thorax, wrapped in a cloth damped with preservative solution, 

 and placed aside for future study. 



When the lung has been removed the margins of the 

 pleural sac must be examined, and their positions relative to 

 the chest wall noted. This cannot be done to the best 

 advantage until both lungs have been removed. When this 

 has been done the dis- 

 sector should introduce 

 one hand into each 

 pleura, and placing an 

 index finger in each 

 apex, he should note 

 that the apex is situated 

 about one inch above 

 the junction of the 

 lateral two-thirds with 

 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 posi- 

 tions. The apices of 

 opposite sides, there- 

 fore, are some distance 

 apart, and are separ- 

 ated from each other 

 by the structures occu- 

 pying the median part. 



FIG. 6. Diagram to show the relation of the 

 lungs and the pleural sacs to the anterior 

 thoracic wall. The lungs are depicted in 

 red, and the pleural sacs in blue. 



of the neck ; i.e. the 

 air tube, the gullet, and the great arteries passing upwards to the 

 head. As the anterior margins of the pleuras are traced down- 

 wards from the apices they will be found to converge, passing 

 behind the sterno-clavicular joints and coming into apposition 

 at the lower border of the manubrium sterni, immediately to 

 the left of the median plane. Traced further downwards the 

 anterior margins remain in apposition, the right frequently over- 

 lapping the left and both inclining slightly to the left, to the 

 level of the fourth costal cartilages. From the fourth cartilage 



VOL. II 2 



