THE PELVIS. 



281 



9. This union is called s"acral plexus to the lower margin of the greater sacro- 

 sciatic foramen, where it continues its course under the name of great sciatic nerve.. 



10. The sacral nerves all send rami communicantes to the pelvic sympathetic 

 plexus, which you have already found, located to the inner side of the anterior 

 sacral foramina, by the side of the rectum and bladder. 



Dissection : (i) Trace the first, second, and third sacral nerves as far into the 

 sacral foramina as possible. Notice ! This must be done with a blunt forceps, 



Hit" Dura mater of . 



LAST TIIORA CIC NER VE 



ILIO- 

 HYPOGASTRIC 



77,70- 

 INGU1NAL 



ILIAC BRANCH 



OF 1LIO- 

 HYl'OGASTRIC 



Gluteus medius 



Gluteal artery 

 SUPERIOR 

 GLUTEAL NERVE 



ORE A T SCIA TIC NER VE 



INFERIOR GLUTEAL 

 NER VE 



SMALL SCIA TIC NER VE 



POSTERIOR PHI1UAHF 

 DIVISION 



GENITO-CRURAL 



GAUD A EQUINA 



Pilum terminate 



EXTERNAL 

 \\ CUTANEOUS 



OBTURATOR 

 Lr.MIto- SACRAL CORD 



-, FIRST 8 A CRA L 

 NER VE 



FIFTH SACRAL 

 NER VE 



VISCERAL BRANCHES 

 Si'inlii- itrlery 



Small sacro-sciatic 



ligament 

 PUDIC NER VE 



NERVE TO 

 OBTURA TOR 

 INTERNUS 



PER FORA TING 

 CUTANEOUS OF 

 SECOND A ND 

 THIRD SACRAL 

 NERVES 



FIG. 194. A DISSECTION OF THE LUMBAR AND SACRAL PLEXUSES, FROM BEHIND. 

 (The anterior crural nerve is placed between the external cutaneous and obturator nerves.) 



and with a very delicate touch, to avoid injuring the small branches given off to 

 the sympathetic pelvic part of the gangliated cord. After this is done, all the 

 fat must be dissolved by ether, benzene, or gasoline. (2) Now dissect in the 

 direction of the branches given off, and find the following : 



BRANCHES OF THE SACRAL PLEXUS. 

 i. Tlic lumbo-sacral cord is the communication between the sacral and lum- 



bar plexuses. 

 19 



It is formed by the fifth lumbar and part of the fourth lumbar 



