Fig. 70. Apex of the Pleura. 



Fyom the neck of a man, aged 40, both clavicles have been removed, Trachea 

 and Oesophagus cut off, and the important vessels and nerves displayed in their 

 relation to the apex of the pleura (which is coloured light blue). On the left 

 side, special attention has been paid to the Veins and the Thoracic Duct; on 

 the right side to the Arteries and the Nerves, in particular, to the Sympathetic. 



The apex of the Pleura ends exactly at the level of the ist rib. This 

 rib which forms with the Sternum and ist Dorsal Vertebra the upper aperture 

 of the Thorax, ascends behind, in an oblique direction. The slope of the apex 

 of the pleura, and the lung within it, corresponds to that of the rib mentioned. 

 An instrument, introduced immediately above the first rib, horizontally backwards, 

 will therefore open the pleura. By percussion, one can also prove the presence 

 of resonant lung about one inch above the clavicle. Despite all this, it is wrong 

 to sa)' that the pleural cavity extends everywhere beyond the upper aperture of 

 the thorax. Normally, it passes above the level of that inclined plane only at 

 one spot, at the middle of the ist rib, and only to the extent of V2 inch. Strands 

 of connective tissue keep the apex of the pleura in position ; this fascia runs from 

 the Cervical Vertebrae and the neck of the first rib to the apical pleura. 



The large vessels and nerves which pass through the upper aperture of 

 tlie Thorax to the head and the upper limb, and the Nerves which go from the 

 neck to the arm are in close relation with the apex of the Pleura. Internal to 

 the latter, on the right side, the Innominate Artery, on the left, the Subclavian 

 Artery passes. The Innominate Artery bifurcates into Common Carotid and Sub- 

 cla\'ian either behind the Sterno-Clavicular articulation or at a higher level. The 

 Subclavian Artery arches over the apex of the Pleura, leaving it at the Scalene 

 Tubercle on the first rib. The Internal Mammary Artery which arises from the 

 Subclavian, before it passes between the Scalenus Anticus and Medius Muscles, 

 is also in relation to the Apex of the Pleura; external to it is the Phrenic 

 Nerve. The Inferior Cervical Ganglion (cf. right side of the figure) lies on the 

 apex, between the Longus Colli Muscle and the arch of the Subclavian Artery, in 

 front of which the Vagus descends (also in relation with the apex of the Pleura). 

 Both Innominate Veins, formed by the Internal Jugular and Subclavian Veins 

 are also relations of the apical pleura, on which the Brachial Plexus, — 

 external to the Subclavian Artery — , rests. Lastly, the Pleura lines the inner 

 border of the Scalenus Anticus Muscle where it is attached to the first rib. 



Disease of the Pleura can, especially on the right side, affect the Recurrent 

 Laryngeal Nerve. 



The fact that so many structures of vital importance are in close ap- 

 position within a small space renders removal of tumours, growing in that region, 

 and ligature of the vessels very difficult and even dangerous. Apart from the 

 possibility of injury to the vessels and nerves in the neighbourhood, there is danger 

 of opening the Pleura. 



