PRACTICAL CONSIDERATIONS : THE LUNGS AND PLEURA. 1867 



muscles, and the abdominal muscles are all supplied by the lower intercostal nerves, 

 the respiratory movements on the affected side are painful and are therefore greatly 

 limited. Accordingly there will be hurried, shallow breathing with a weak vesicular 

 murmur on the affected side and exaggerated respiratory sounds on the opposite 

 side. Pain and tenderness in the epigastrium may result from implication of the 

 trunks of the lower intercostal nerves when the pleurisy is near the base of the chest. 

 When it is higher the pain may be felt in the axilla and down the inner side of the 

 arm from involvement of the intercosto-humeral nerve, or in the skin over the seat 

 of disease through the lateral cutaneous branches of the upper intercostals (Hilton). 

 In diaphragmatic pleurisy the pain may be intensified by pressure over the point of 

 insertion of the diaphragm into the tenth rib (Osier). 



Pleural effusion {hydrothorax, empyema), in addition to the signs already 

 described (vide supra), causes, when it is of sufficient amount, additional symptoms, 

 as bulging of the side of the chest with obliteration of the intercostal spaces, disten- 

 tion of the net- work of superficial veins (from pressure on the vena cava or greater 

 azygos vein), and displacement of other viscera. If the fluid occupies the left 

 pleura, as its weight depresses the diaphragm, the pericardium, which is attached to 

 the central tendon, descends also, and with it the apex of the heart. At the same 

 time the heart is pushed towards the right so that the apex beat may be felt in the 

 epigastrium (Owen). 



An empyema may point and discharge itself spontaneously, in which case it 

 often does so at about the fifth interspace just beneath and external to the chondro- 

 costal junction (Marshall). At this place the chest- wall is exceptionally thin, as the 

 region is internal to the origin of the serratus magnus, external to the insertion of 

 the rectus, and above the origin of the external oblique (McLachlan). 



Evacuation of the fluid may be effected by paracentesis in pleurisy with serous 

 effusion through the sixth or seventh intercostal space in the mid-axillary line, or 

 through the eighth or ninth space just anterior to the angle of the scapula. The 

 same regions are selected for thoracotomy incision and drainage in empyema. The 

 former site is usually preferred for anatomical reasons already given (page 170). 



Pneumonia is often limited to one lobe of a lung, usually the lower. The fis- 

 sure between the two lobes of the narrower left lung runs from the third rib behind, 

 or from about the third dorsal spinous process or the inner end of the spine of the 

 scapula, to the base in front. The fissure between the two lobes of the right lung 

 begins at about the same level behind and extends to the base of the lung anteriorly. 

 Where it crosses the posterior axillary line a second fissure springs from it which 

 passes horizontally forward to the fourth chondro-costal junction making the middle 

 lobe. Both lower lobes are posterior to the anterior lobes, and on both sides the 

 fissures run from the level of the inner end of the spine of the scapula behind to the 

 base in front. Therefore the dulness, crepitant rales, bronchial breathing, and 

 increased vocal fremitus of a lobar pneumonia affecting the base would often be below 

 that line posteriorly and would be less marked in front ; while the flatness, prolonged 

 expiration, and other physical signs of a tuberculous infection (which affects by 

 preference the upper lobe) would be above the spine of the scapula posteriorly, and 

 lower would be more marked anteriorly. 



The relations of the lungs to the thoracic walls have been described in detail 

 (page 1855). 



The congestion and oedema which precede the so-called ' ' hypostatic pneumonia' ' 

 are very apt to begin in the thick lower and posterior portions of the lower lobes in 

 weak or aged persons kept long in the supine position. 



Tuberculous infection of the lungs is found oftenest in the apices, probably 

 because of the relatively defective expansion in that region which exists in all persons, 

 and particularly in those of the so-called phthisical type, with round shoulders, long 

 necks (page 143), and flat chests ; possibly also because of the greater exposure to 

 changes of external temperature ; and perhaps somewhat owing to the short distance 

 intervening between the outside atmosphere and the ultimate bronchioles where 

 tuberculous pulmonary disease usually has its inception. 



The physical signs are those indicating consolidation followed by softening or 

 the formation of a cavity (vide supra}. 



