CHAPTER VII. 

 THE CHEST. 



The chest or thorax occupies the upper part of the 

 trunk in front and is a dome-shaped cavity containing 

 and protecting the heart and lungs. Its walls are formed 

 by the dorsal vertebrae at the back, the ribs at either side, 

 and the sternum and costal cartilages in front, all well 



Circumference of apex of thorax. 



First rib. 



Second rib. 



Third rib. 



Seventh rib. 



Eighth rib. 



Ninth rib.- 

 Tenth rib 



Eleventh rib, 



Manubrium 

 sterni. 



Costal cartilages. 

 Gladiolus. 



Ensiform carti- 

 lage or xiphoid 

 appendix. 



Eleventh rib. 



Circumference of base. 

 FIG. 36. Thorax (anterior view.) (Ingals.) 



covered with muscles. The floor is formed by the 

 diaphragm. Through the upper opening of the chest 

 pass the trachea, the esophagus, and many important 

 vessels and nerves. 



The shape of the chest may vary in disease. Thus, in 



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