FIG. 1564- 



Apex 



Groove for subclavian 

 artery 



Groove for 

 innominate vein 



Superior 

 lobe 



Middle 

 iobe 



\ Ease 



Inferior lobe 



HUMAN ANATOMY. 



causing the expansion which makes the outline triangular, the inferior vein being in the 



1, rwer angle. The inner surfaces are also marked by certain adjacent structures which 



require a separate account for each lung. 



The right lung presents a vertical groove 



above and in front for the superior vena 



cava, and one for the vena azygos major, 



which is distinct behind the upper part 



.,f the hilum and above it where this 



vein runs forward to the cava. The right 



subclavian artery, owing to its high origin 



from the innominate, indents but little of 



the internal surface. A more or less 



marked vertical groove for the oesophagus 



is seen behind the hilum and below that 



for the azygos. There is also a groove 



below on the inner surface where the in- 

 ferior vena cava turns forward to enter the 



heart. A slight impression made by the 



trachea may also be present near the 



apex. The inner surface of the left lung 



is deeply grooved by the aorta arching 



over the root and descending behind it, 



the imprint growing faint and disappear- 

 ing at the lower end. The left carotid 



and subclavian arteries make distinct 



impressions at the upper part diverging 



from the aortic groove. 



The base (facics diaphragmatica) is 



concave, that of the right one being 



rather the more so. Both are semilunar in outline, owing to the part cut out 



of them by the heart ; since this encroachment is greater on the left, the base 



of that lung is a narrower 

 1 5 6 5- crescent. 



The inferior border 

 surrounds the base. The 

 latter forms about a right 

 angle with the internal sur- 

 face, but at the periphery, 

 especially at the back and 

 at the side, a sharp edge 

 of lung is prolonged down 

 into the narrow space be- 

 tween the diaphragm and 

 the thoracic walls. The 

 anterior border is sharp 

 and somewhat irregular, 

 often presenting a series of 

 convexities. Starting near 

 the apex, it descends on 

 both lungs with a forward 

 curve, which is most promi- 

 nent in the upper part, so 

 that the lungs nearly or 

 quite meet behind the ma- 

 nubrium. The anterior bor- 

 der of the right lung then 

 inclines downward and out- 

 curve. On the left this convex- 



Right lung, hardened in situ; antero-lateral aspect. 



FIG. 



Groove for 

 innominate artery 



Groove for right 



iniioinin.tu- M-III 



Groove for 

 ena azygos major 



am bronchus 



Preceding lung ; median aspect. 



! n as to meet tin- inferior border in a gradual curve, un tne leit tins convex- 

 ity is changed mt.. :\ *lurp .,,iu-avity where the border curves outward around the 



