464 TOPOGRAPHICAL ANATOMY. 



forming between the lobes ligg. inter tabular ia, and at the roots of 

 the lungs covering the parts entering and passing out. 



716. II. Lungs. Each of the two lungs rests with the con- 

 cave basis upon the convex surface of the diaphragm. The 

 rounded apex reaches about one inch above the first rib. Their 

 convex external surface is turned towards the concavity of the 

 ribs, and shows on the right lung two incisurce interlobulares 

 passing from behind forwards, on the left one incis. inter tabular., 

 so that the former is divided into three, the latter into two lobes. 



717. HI. Pericardium, extends from the point of junction of 

 the sixth and seventh rib cartilage with the sternum of the right 

 side : a rhomboidal piece of its anterior surface looks freely into 

 the cav. mediast. anticum. It envelopes 



718. IV. The Heart, the posterior inferior surface of which 

 rests upon the diaphragm, the basis of which lies to the right, 

 above and behind as high as the sixth dorsal vertebra, the apex 

 to the left, in front and below, behind the anterior extremity of 

 the cartilage of the sixth and seventh left ribs. Sulcus longi- 

 tudinalis, transversus. Ventriculi, atria and auricula cordis 

 (see Heart, 527.) 



Besides the coronary veins, there open into the heart : 

 1. Vena cava superior, formed by the junction of the two 

 anonymce. [ven. brachio-cephalicte] behind the first and second 

 right costal cartilages, passes before art. pulmonal. dextra, to the 

 right and rather behind the commencement of the Aorta, into the 

 atrium dextrum. 



a. V. anonyma dextra [right brachio-cephalic] lies perpendicu- 

 larly before the first (right) costal cartilage, before and inter- 

 nal to nerv. phrenic, dexter and art. mamm. intern, dextra. 



b. V. anonym, sinistra [left brachio-ceph.] horizontal behind 

 the manubrium, close above arcus aorta, before art. 

 anonyma, carotis and subclavia sinistra. 



3. V. cava inferior, passes through foramen quadrilaterum of 

 the diaphragm from the ventral into the thoracic cavity, and im- 

 mediately into the pericardium, where it turns forwards and to 

 the left, and before the eighth and ninth dorsal vertebra sinks into 

 atrium dextrum. 



3. Vena, pulmonales, pass forth with two trunks from the root 

 of each lung, lie behind and below the other large blood-vessels of 

 the heart and behind the bronchi, advancing towards those of the 

 opposite side, and opening into the atrium sinistrum. 



From the heart arise, besides the coronary arteries, 



