34 UNIVERSITY OF MISSOURI STUDIES 



space in the midclavicular line, at the upper border of the 

 seventh rib in the midaxillary line, and over the head of 

 the tenth rib at the side of the vertebral column. The 

 inferior margin of the left lung begins anteriorly in the 

 fifth intercostal space near the midclavicular line and passes 

 behind the seventh rib in the midaxillary line to end in 

 the tenth intercostal space at the side of the vertebral 

 column. 



The base of the right lung is separated by the 

 right dome of the diaphragm from the right lobe of the 

 liver. Since the middle lobe of the lung forms the ante- 

 rior part of the base it enters into relation with a corres- 

 ponding portion of the right lobe of the liver. The larger 

 posterior part of the base of the lung is formed by the in- 

 ferior lobe which is in relation with the remainder of the 

 superior and a portion of the posterior surface of the right 

 lobe of the liver. The inner and posterior part of the base 

 is in relation with the vena cava inferior for the very short 

 distance that that vessel is in the thoracic cavity between 

 the vena caval opening through the diaphragm and that into 

 the heart. Below the caval opening through the diaphragm 

 the lung is separated from the vena cava inferior by the 

 diaphragm (Plate XIII). The projections show the lung 

 overlapping the liver only about 3 cm. This condition is 

 probably due to the lung being in a condition of extreme 

 expiration. During inspiration the lung margin may be 

 pushed down into the costophrenic sinus several centime- 

 ters lower than is found in this subject. 



The base of the left lung is in relation with the left 

 lobe of the liver, the stomach, and the spleen. The liver 

 extends from the midline of the body outward and a little 

 backward, filling the central portion of the left dome of 

 the diaphragm. It is in relation with the central portion 



