INTERCOSTAL ARTERIES. 



403 



is separated from the pleura by a fascia only, but further outwards it lies 

 between the two layers of intercostal muscles. Extending forwards in con- 



Fig. 281. VIEW OF THE Fig. 281. 



THORACIC AND UPPER 

 PART OF THE ABDOMINAL 

 AORTA, &c. 5 



For the general descrip- 

 tion of this figure, see p. 334. 

 The following numbers in- 

 dicate the branches of the 

 aorta ; 1, placed between 

 the origins of the right and 

 left coronary arteries ; 2, 

 innominate ; 3, left carotid ; 

 4, left subclavian ; 5, bron- 

 chial ; 6, 6, cesophageal ; 7, 

 7, intercostal arteries (sixth 

 and seventh) ; 8, inferior 

 phrenic ; 9, cceliacaxis ; 10, 

 below the superior mesen- 

 tei ic and opposite the origin 

 of the renal arteries; il, 

 11, two of the lumbar 

 arteries. 



tact with the rib above, 

 it finally anastomoses 

 with one of the anterior 

 intercostal branches de- 

 rived from the inter- 

 nal mammary artery, 

 and with the thoracic 

 branches of the axillary 

 artery. 



The first of the aortic 

 intercostal arteries has 

 an anastomosis with the 

 superior intercostal pro- 

 ceeding from the sub- 

 clavian artery ; and the 

 last three are prolonged 

 into the abdominal mus- 

 cles, where they com- 

 municate with the epi- 

 gastric artery in front, 

 with the phrenic arteries 

 at the side, and with 

 the lumbar branches of 

 the abdominal aorta 

 lower down. 



Each intercostal ar- 

 tery is accompanied, as 

 it runs outwards be- 

 tween the ribs, by a corresponding vein, and by one of the dorsal nerves > 

 the vein being usu illy uppermost, and the artery next below it. 



