|Henry Gray (18251861). Anatomy of the Human Body. 1918.|
|the fourth interspace of the right side. The lines indicating the atrioventricular 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 midsternal 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 opposite the summit of the arch, and a line from it to the right sternoclavicular articulation 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 tricuspid 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. (See enlarged image)
| 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 sternoclavicular 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 midsternal line.