ANATOMY IX A NUTSHELL. 



255 



monary. The lungs are two large organs which occupy a great part of the chest 

 cavity. The heart, oesophagus, and the great vessels separate them. They 

 are the organs of respiration in air breathing vertebrates and communicate 

 with the pharynx through the trachea. The air cells (alveoli) are from one 

 fiftieth to one-seventieth of an inch in diameter. The lungs are formed by re- 

 peated subdivisions of the bronchial tubes which finally end in saccular dilata- 

 tions called infundibula. The air cells are in the infundibula and the air pass- 



UPPER FASCICULUS 

 MIDDLE FASCICULUS. 

 .OWER FASCICULUS. 



PLATE CIV. 



_-*-> THREE SLIPS OF THE STELLATE LIGAMENT 



ANTERIOR COSTOVERTEBRAL LIGAMENT 



ANTERIOR OR SUPERIOR COSTOTRANSVERSE LIGAMENT 



Ligaments of Spinal Column. 



ages leading to them. These cells have a capillary net-work in which the 

 branches of the pulmonary art< ry < nd and In re the blood is s< parat< d from the 

 air by the capillary wall and the thin alveolar epithelium of the air cells. The 

 lung is comparatively compact, being composed of air breathing tubes bound 

 tip by connective tissue. 



Blood Supply. — From the bronchial arteries which vary in number, size. 

 and origin. The one on the right side may conic from (1) the first aortic in- 

 tercostal. (2) by a common trunk with the lefl bronchial from the f I of the 



thoracic aorta. On the left side ther< are generally two which conic from the 

 thoracic aorta. The bronchial veins do not return all the blood carried to the 



