ARTERIA INNOMINATA. 



281 



Thoracic aorta 



.Abdominal aorta 



Branches. The branches of the aorta, arranged into a tabular form, 

 are, 



Ascending aorta . . Coronary. 



f . . . . ( Right carotid, 



C Artena innominate, R | ht subda ; ian- 



Jirch of the aorta . . < Left carotid, 



f Left subclavian. . 

 Pericardiac, 

 Bronchial, 

 CEsophageal, 

 Intercostal. 

 Phrenic, 



C Gastric, 

 Coelic axis, < Hepatic, 



( Splenic. 

 Supra-renal, 

 Renal, 



Superior mesenteric, 

 Spermatic, 

 Inferior mesenteric, 

 Lumbar, 

 Sacramedia, 

 Common iliacs. 



The CORONARY ARTERIES arise from the aortic sinuses at the commence- 

 ment of the ascending aorta, immediately above the free margin 01 the 

 semilunar valves. The left or anterior coronary, passes forwards, be 

 tween the pulmonary artery and left appendix auricula?, and divides into 

 two branches ; one of which winds around the base of the left ventricle in 

 the auriculo-ventricular groove, and inosculates with the right coronary, 

 forming an arterial circle around the base of the heart ; while the other 

 passes along the line of union of the two ventricles, upon the anterior as- 

 pect of the heart, to its apex, where it anastomoses with the descending 

 branch of the right coronary. It supplies the left auricle and the anterior 

 surface of both ventricles. 



The right, or posterior coronary, passes forwards, between the root of 

 the pulmonary artery and the right auricle, and winds along the auriculo- 

 ventricular groove, to the posterior median furrow, where it descends upon 

 the posterior aspect of the heart to its apex, and inosculates with the left 

 coronary. It is distributed to the right auricle, and to the posterior surface 

 of both ventricles, and sends a large branch along the sharp margin of the 

 right ventricle to the apex of the heart. 



ARTERIA INNOMINATA. 



The Jlrteria innominata (fig. 145, No. 4) is the first artery given oflfby 

 the arch of the aorta. It is an inch and a half in length, and ascends 

 obliquely towards the right stern o-clavicular articulation, where it divides 

 into the right carotid and right subclavian artery. 



Relations. It is in relation, in front, with the left vena innominata, the 

 thymus gland, and the origins of the sterno-thyroid and sterno-hyoid mus- 

 cles, which separate it from the sternum. Behind, with the trachea, pneu- 

 24* 



