608 



THE LUNGS. 



The interlobular surfaces formed by the several fissures 

 entering into the lungs, are all free, smooth, and covered 



Fig. 197. 



"by pleura, and increase to an immense extent the area 

 for the cells. 



Structure, (Fig. 197.) The different elements constituting 

 the lungs are the bronchial tubes, pulmonary arteries, pul- 

 monary veins, bronchial arteries and veins, lymphatic vessels 

 and nerves, all connected by cellular tissue and covered by 

 pleura. These several tissues before entering the lungs 

 are all collected into a small compass, and known by the 

 name of the root of the lungs. This root is about an inch 



FIG. 197 represents the distribution of the Bronchise and Blood-vessels, with 

 the relation of the Lungs and Heart. 1 Left auricle. 2 Right auricle. 3 

 Left ventricle. 4 Right ventricle. 5 Pulmonary artery. 6 Arch of aorta. 

 7 Superior vena cava. 8 Arteria innominata. 9 Left carotid artery. 10 Left 

 subclavian. 11 Trachea. 12 Larynx. 13 Superior lobe of right lung. 14 

 Superior lobe of left lung. 15 Right pulmonary artery. 16 Inferior lobe of 

 the lungs. 



