CHAPTER X 

 THE THORAX AND ITS CONTENTS 



The body cavity must be opened in a manner which will 

 destroy the least number of important structures, guard against 

 dessication of the contents and at the same time permit ready 

 access to the internal structures. Great care must be exercised 

 in opening the body cavity to prevent mutilating the thoracic, 

 or abdominal, viscera. It is also imperative that the wall of the 

 thorax be excised in a single piece which is left attached to the 

 abdominal wall, as directed under method. All of the ribs, 

 except the first, of the left side are to be cut free at their sternal 

 and vertebral ends and the second rib must be freed from the 

 first so that this mass, containing the major portion of the 

 second to twelfth ribs and comprising almost the entire left 

 thoracic wall, can be flexed onto the abdomen, thus exposing 

 the thoracic viscera. 



Method: (a) Make an incision through the abdominal cavity 

 near the diaphragm and about 3 cm. to the left of the linea alba, 

 explore with the finger and then continue the incision craniad 

 through the margin of the diaphragm and last two true costal 

 cartilages. Insert the grooved director craniad through this 

 opening and push its point through the muscles between the 

 first and second ribs at a point about two cm. laterad to the 

 sternum and with the scissors transect all the costal cartilages 

 craniad including the first. It is now possible to insert the 

 fingers into the thoracic cavity and explore the region for the 

 next two incisions which will complete the excision of the left 

 thoracic wall. 



{h) Transect the muscles binding the second rib to the first 

 from the sternal incision (a) to the dorsal margin of the thoracic 

 cavity, which is determined by digital exploration. (The 



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