i855 



HUMAN ANATOMY. 



Apart from variations in the lungs themselves, the different shapes and sizes ot 

 the chest, with the consequent differences in the inclination of the ribs, make these 

 relations very uncertain, especially at the side. In forced respiration there is no 

 change in the relations of the top of the lungs and the dome of the pleura, as they 

 are always in close apposition, and but little change in the first part of the anterior 

 borders. The latter, however, approach one another behind the sternum in forced 

 inspiration, a considerable advance of the left lung taking place at the cardiac notch. 

 We agree with Hasse that during inspiration the anterior parts of the lungs rise 

 just about as much as the thoracic walls. The greatest changes of relations are below 

 and at the side. It is said that in the axillary line the border may descend as much 

 as from 3-4 cm., and at the back as much as 3 cm. According to Hasse,' the 

 lower border of the lung in the axillary line never descends nearer to the lower edge 

 of the thoracic wall than 7 cm. on the right and 5 cm. on the left. He finds that in 



Fig. 1380. 



Semidiagrammatic reconstruction, showing relations of pleural sacs (blue) and lungs (red) to thoracic wall; 



anterior aspect. 



extreme expiration the lower borders of the lungs rise in the axillary lines to 13 cm. 

 on the right and 14 cm. on the left above the lower border of the chest. He states 

 also that the anterior borders may withdraw to the parasternal lines (vertical lines 

 dropped from the inner third of the clavicles), which to us appears excessive. In 

 our opinion, the great factor in the expansion of the lungs is the increase in the vari- 

 ous diameters of the chest rather than the changes of relation of the borders of the 

 lungs to the walls. 



The relations of the fissures to the surface are rather variable. The chief ones 

 ascend from the hila and reach the posterior surface at the sides of the vertebral col- 

 umn, generally at different levels, the right being the lower. We must, therefore, 



^ Die Formen des menschlichen Korpers und die Formanderungen bei der Athmung, 

 |ena, 1888 and 1890, 



