286 



PRACTICAL ANATOMY. 



Visceral Relations. On careful dissection you will see the diaphragm bears 

 very important relations to the following structures : (i) As previously indicated, 

 the superior surface of the diaphragm is occupied by the three serous membranes. 

 The pulmonary surface of the diaphragm corresponds to the base of the lung. 

 The cardiac surface corresponds to the base of the pericardium. (2) The liver, 

 stomacli, spleen, kidneys, and suprarenal capsules are in relation with its under 

 surface. (3) The aorta, oesophagus, ascending vena cava, the vena azygos minor, 

 the pneiiinogastric nerves, the splanchnics, the sympathetic all pass through the 

 diaphragm. (4) Posteriorly, the diaphragm arches over the psoas magnus and 

 the quadratus lumborum. A fibrous arch, formed by the iliac fascia, arches over 

 the psoas ; one formed by the anterior layer of the lumbar fascia arches over the 

 quadratus lumborum muscle. Consult carefully figure 195. Lastly, remove 

 the peritoneal covering of the diaphragm, and see the beautiful manner in which 

 the fibers from the three different sources of origin approach for insertion the 



Sternal origin 



Opening for vena 

 cava inferior 



Right division of 

 tendon 



Middle division 

 of tendon 



(Esophagus 



Left division of 

 tendon 



- Costal origin 



Ligamentum 

 arcuatum 

 internum 

 Left cms 

 Ligamentum 

 arcuatum 

 externum 

 Transverse 

 process of 

 second lumbar 

 vertebra 

 Fourth lumbar 

 vertebra 



Quadratus 

 lumborum 



FIG. 195. DIAPHRAGM. 



central tendon. The central tendon corresponds to the base of the pericardium ; 

 the fibrous part of the pericardium is the downward prolongation and expansion 

 of the third layer of the deep cervical fascia, having firm bony attachments to 

 the base of the skull ; hence, in deep inspiration it is not the central tendon that 

 becomes depressed, but the muscular part of tlie diaphragm. 



Dissection of Deep Muscles and other Structures of the Pelvis. (i) The quad- 

 ratus lumborum ; (2) psoas parvus ; (3) psoas magnus ; (4) iliacus ; (5) crura of 

 diaphragm ; (6) anterior common ligament of vertebral column ; (7) obturator 

 internus ; (8) obturator extemus ; (9) obturator membrane; (10) pyriformis ; 

 (i i) coccygeus 1(12) levator ani ; (13) white line of the obturator fascia. 



