98 TOPOGRAPHIC AND APPLIED ANATOMY 



PLATE 7. 



A posterior view of a dissection of the thoracic, and of a portion of the cervical viscera. The relation of the bronchi, 

 arteries, and veins at the hilus of the lungs. From a Leipzig model from nature (His). 



occasionally encountered in the infraclavicular fossa in ligating the first portion of the axillary 

 artery (see page 73 and Fig. 28). 



The Inferior Boundary of the Thorax. The diaphragm forms a muscular dome-shaped 

 partition which constitutes the inferior boundary of the thorax. The right side of the dome, 

 which covers the liver, projects upward more markedly than does the left side. The central 

 tendon is flatter and has a more restricted range of motion during respiration (review the lumbar, 

 costal, and sternal portions of the muscle with their origins). The structures passing through 



Vena azygos 



major 

 Esophagus 

 Right inferior 

 pulmonary vein 



Right phrenic f "" 

 nerve \ ~ 



Foramen quad-. 



ratum 



-Sternum 



Vertebral arch 

 Spinal cord 



Body of vertebra 



Vena azygos 

 minor 

 Thoracic 



descending aorta 



Diaphragm 

 Pericardium 



Left phrenic 

 nerve 



FIG. 44. The diaphragm and the inferior half of the pericardium seen from above. Formalin preparation (child). 



the diaphragm from above downward are: the descending aorta through the aortic opening; 

 the esophagus and the pneumogastric nerves through the esophageal opening; the splanchnic 

 nerves, from the sympathetic, between the crus mediale and the crus intermedium of the lum- 

 bar portion; the sympathetic nerve itself between the crus intermedium and the crus laterale 

 of the lumbar portion; and the superior epigastric artery, from the internal mammary between 

 the sternal and costal portions (the so-called fissure of Larrey). The structures passing through 

 the diaphragm from below upward are: the inferior vena cava (accompanied by a filament from 

 the right phrenic nerve), through the foramen quadratum in the right side of the central tendon; 

 the vena azygos major (on the right side) and the vena azygos minor (on the left side), accom- 



