LARYNX 



133 



patent by rings of cartilage, which, however, are not complete 

 posteriorly, so the organ is not quite cylindrical. These cartila- 

 ginous rings are continued in the bronchi. 



The trachea follows the curve of the vertebral column, so 

 passes obliquely backwards as it descends. It is in the middle 

 line until the bifurcation is reached, where it lies slightly to the 

 right. 



The Bronchi pass obliquely downwards aud outwards from 

 the bifurcation of the trachea to the roots of the lungs. The 



Superior Cornu of Thyroid 

 Cartilage 



Isthmus (Pomum Adami) 



^~*Crico-thyroid Ligament 



Cricoid Cartilag= 



FIG-. 52. THE LARYNGEAL CARTILAGES. 



right bronchus is shorter and wider than the left, and is not so 

 obliquely placed. The bronchi have several branches passing to 

 the different lobes of the lungs. 



The Lung's lie within the pleural cavities of the thorax. A 

 perfectly healthy lung lies quite free within its own pleural sac, 

 attached only by its root ; but as a rule adhesions between the 

 lung and pleura are found. The right lung is larger than the 

 left, the proportion being about eleven to ten . It is also shorter 

 and wider. 



The lungs take the shape of the pleural cavities, and are 

 conical structures having an apex which projects above the level 

 of the first rib for about half an inch, and a concave base 

 which is adapted to the cupola of the diaphragm, on which it 

 rests. The outer surface is smooth and convex, except for shal- 

 low grooves made by the ribs, and the inner surface has the 



