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, 

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

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

 the pucumogastric nerves, the splancJmics, 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 



Aorta - -i 



Bight crus 

 Psoas parvus 



Psoas 



Transversalis 

 abdominia 



Middle division 

 of tendon 



(Esophagus 



Left division of 

 tendon 



'.- Costal origin 



Ligamentum 



arouatum 



internum 

 Left crus 

 Ligamentum 



arcuatum 



externum 

 Transverse 



process of 



second lumbar 



vertebra 

 Fourth lumbar 

 vertebra 





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 expansioi 

 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 diapliragm. 



I Dissection of Av/> Muscles and otlicr Structures of tlic Pelvis. (i) The quad- 

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

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

 interims ; (8) obturator extern us ; (9) obturator membrane; (10) pyriformis 

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





