JRFACE ANATOMY AND 



MARKINGS 





the fourth interspace of the right side. The lines indicating the atrio ventricular 

 openings are slightly below and parallel to the line of the coronary sulcus. 



Arteries. The line of the ascending aorta begins slightly to the left of the mid- 

 sternal line opposite the third costal cartilage and extends upward and to the 

 right to the upper border of the second right costal cartilage. The beginning of 

 the aortic arch is indicated by a line from this latter point to the midsternal line 

 about 2.5 cm. below the jugular notch. The point on the midsternal line is oppo- 

 site the summit of the arch, and a line from it to the right sternoclavicular articu- 

 lation represents the site of the innominate artery, while another line from a point 

 slightly to the left of it and passing through the left sternoclavicular articulation 

 indicates the position of the left common carotid artery in the thorax. 



FIG. 1218. Diagram showing relations of opened heart to front of thoracic wall. Ant. Anterior segment of tri- 

 cuspid valve. A O. Aorta. A. P. Anterior papillary muscle. In. Innominate artery. L.C.C. Left common carotid 

 artery. L.S. Left subclavian artery. L.V. Left ventricle. P. A. Pulmonary artery. R.A. Right atrium. R.V. 

 Right ventricle. V.S. Ventricular septum. 



The internal mammary artery descends behind the first six costal cartilages 

 about 1 cm. from the lateral sternal line. 



Veins. The line of the right innominate vein crosses the right sternoclavicular 

 joint and the upper border of the first right costal cartilage about 1 cm. from the 

 lateral sternal line; that of the left innominate vein extends from the left sterno- 

 clavicular articulation to meet the right at the upper border of the first right 

 costal cartilage. The junction of the two lines indicates the origin of the superior 

 vena cava, the line of which is continued vertically down to the level of the third 

 right costal cartilage. The end of the inferior vena cava is situated opposite the 

 upper margin of the sixth right costal cartilage about 2 cm. from the mid- 

 sternal line. 



