PHYSIOLOGY: PRACTICUM IV: PLATE VIII. 

 DIAPHRAGM OF THE CAT. CEPHALIC OR THORACIC ASPECT. 



neurapophysis 



MYEI, (spinal cord) 



centrum of vertebra 



muscle 



various vessels, etc. 



AORTA 

 , thoracic septum 



'ESOPHAGUS 



' POSTCAVA 



This is the view presented after the thorax has been cut away as at the close of Practi- 

 cum III. The diaphragm is seen from the right side in Figs. 7 and 8 and the caudal (ab- 

 dominal) aspect is represented in Anatomical Technology, Fig. 90 ; in that figure the dor- 

 sal side is down, here it is above. The ventral portion of the THORACIC SEPTUM ap- 

 pears in PI. VII. 



1, conjoined PLEURAS of right and left sides forming the left wall of the pocket for 

 the azygous lobe of the lung seen in Practicum III, \ 25. 



2, right wall of the same ; this is attached to the postcava, and the interval between the 

 postcava and the esophagus permits the connection of the azygous lobe with the rest of the 

 lung. 



3, interval between the thoracic wall and the ventral convexity of the diaphragm. 



9, 10, 12, ends of the corresponding CARTILAGES ; the eleventh is crossed by the line 

 from the postcava. 



13, cut end of the thirteenth RIR. 



Points illustrated. A. The diaphragm is a dome, mostly of muscular fibers converg- 

 ing from the peripheral attachment to a CENTRAL TENDON. 



B. It is traversed by three large tubes, the AORTA, ESOPHAGUS, and POSTCAVA. 



C. The PLEURA (thoracic serosa) which covers its surface is reflected upon those 

 tubes so that there is no crevice between them and the diaphragm. 



D. The right and left sides of the thorax are separated by these tubes and by inter- 

 vening double layers of pleura. 



E. The general arrangement of organs and cavities which characterizes the verte- 

 brates ; there is a dorsal cavity containing the mvel representing the NEURAXIS (cerebro- 

 spinal axis) and a ventral containing the esophagus representing the ENTERON (aliment- 

 ary canal) and chief blood-vessels 



