CHAPTER XII. 

 LUNG. 



ANATOMY. LANDMARKS FOR LUNGS. 



LANDMARKS FOR PLEUR/E. 



The right lung is shorter than the left, because of the 

 higher position of the diaphragm on the right side. It is 

 broader than the left, on account of the inclination of the 

 heart to that side. Each lung is composed of an apex ex- 

 tending into the neck, of a base resting on the diaphragm, 

 of an internal surface in contact with the pericardium and 

 the great vessels above the pericardium, of an external 

 surface, applied to the inner wall of the thorax, of an an- 

 terior border, thin and sharp, and of a posterior border, 

 rounded and wide, resting in the groove on the side of the 

 bodies of the vertebrae. The lung is held in its place by 

 the elasticity of its tissues, and by the atmospheric press- 

 ure present in its interior. It is supported by the root and 

 by the broad ligament. The root of the lung is about one 

 and three-quarter inches, from above, downwards, and 

 one inch, from before, backwards, and is situated a little 

 above the middle of the internal surface of the lung and a 

 little nearer the posterior than the anterior border. The 

 root is composed of the bronchus, the pulmonary artery 

 and veins, the bronchial artery and vein, the pulmonary 

 plexus of nerves, lymphatic glands and areolar tissue. 

 Relations of the root of the lung. On the right side there 

 are in front of it; the anterior pulmonary plexus, the 

 phrenic nerve, the right auricle, the ascending aorta and 

 the superior vena cava; above, the vena azygos major 

 arches over the root to empty into the superior vena cava ; 

 behind, are the posterior pulmonary plexus and the pneu- 



