THE THORAX AND PLEURAE — THE LUNGS 



547 



THE THORAX AND PLEURA 



The ribs are in general strongly curved in most of the improved breeds, so that 

 the thorax is rounded. The pleural sacs extend forward to the first intercostal 

 space. The diaphragmatic line of pleural reflection begins at or a little above the 

 sternal end of the seventh rib, and extends in a gentle curve to about the middle of 

 the last rib, along the medial face of which it continues. (When a fifteenth rib is 

 present — a very common occurrence — it does not affect the arrangement of the 

 pleura or diaphragm). 



Trachea QiJsophagus 



Apical lobe 



liac lube 



Cardiac lobe 



Diaphrag- 

 matic lobe 



Diaphrag- 



iiintic lobe 



Fig. 486. — Lungs and Heaet of Pig; Venthal View. 

 L. i., Intermediate lobe of right lung; F. d.. diaphragmatic surface of lungs; 1, left brachial artery; 2, brachio- 

 cephalic artery; S, apex of heart; ^, pericardium (cut edge) ; 5, plica vense cava; 6, posterior vena cava; 7, ceaophagua; 

 8, ventral cesophageal nerve trunk; 9, aorta. 



THE LUNGS 

 The right lung has four lobes— apical, cardiac, diaphragmatic, and intermedi- 

 ate. In some cases the apical lobe is divided by a fissure into two parts; sometimes 

 it is fused with the cardiac lobe. The left lung may be regarded as having two or 

 three lobes. The diaphragmatic lobe is clearly marked off by a fissure. The part 



