166 



latiuu of the Pleura. 



heard only duriiiii" inspiration, eventually onh" toward its end; 

 sometimes both during inspiration and expiration. Exclusive 

 expiratory sounds are rare. The sounds are frequently inter- 

 rupted for short periods. 



A deviation from the behavior of the friction sounds occurs when they are 

 caused by rough portions of the pleura which are in immediate contact with the 

 parietal layer of the pericardium (pericarditis externa) ; then the possibility exists 

 that the friction sounds are synchronous with the contractions of the heart muscle. 

 Under these conditions the friction sounds depend more upon the apex-beat 

 (pleuro-pericardial sounds), but they are also influenced by the respiration and 

 either accompany the inspiratory or the expiratory movements synchronously with 

 the heart sounds, while they may also be observable during the pause of the lieart 

 sounds, but with the resi)iratory movements. Such sounds are, of course, only heard 

 in the cardiac region and more frequently on the left than on the right side. 



Fig. 25. Horizontal lino of dullness in pleurisy with iluid exudate (Tubercu- 

 losis). 



In pleurisy with a fluid exudate the picture so far de- 

 scribed is altered very considerably. The respiratory move- 

 ments are now usually less accelerated, but are deepened and 

 forced in proportion to the amount of fluid present (flank 

 breathing). During inspiration the ribs are elevated and there 

 is a distinct trembling of the vertebral column and of the whole 

 rump at the beginning of expiration. Expiration takes place 

 in two stages and produces a groove parallel to the costal arch 

 at the be.ginning of expiration; the flank depressions become 

 prominent simultaneously, and the lumbar portion of the ver- 

 tebral column occasionally curves upward. In very severe 

 cases, a pumping respiration is observed. The patients also 

 manifest other symptoms of dyspnea. 



