812 



THE XERVOUS SYSTEM 



border of the gluteus maximus, and, having pierced the deep fascia, supply the 

 inteo-unient covering the lower and outer ])art of that muscle. 



(6) The long pudendal nerve, or nerve of Soemmerring, winds round the 

 origin of the hamstring muscles, just below the ischial tuberosity, giving twigs to 

 thiTintegument on the inner and upper part of the thigh, and then curves upwards 

 and forwards towards the external genitals. Having pierced Colics' s fascia, it 

 connnunicates with the superficial perina^il nerves, and ends in the integument of 



Fig. 466.— a Dissection of the Lumbar and Sacral Plexuses, from behind. 

 (The anterior crural uerve is placed betweeu the external cutaneous and obturator nerves.) 



TWELFTH RIB 



LA^T THORACIC NERVE 



ILIO- 

 HYPOGASTRIC 



ILIAC BRANCH 



OF ILIO- 

 HYPOGASTRIC 



Gluteus medius 



Gluteal artery 

 SUPERIOR 

 GLUTEAL NERVE 



GREA T SCIA TIC NER VE 



INFERIOR GLUTEAL 

 NER VE 



SMALL SCIATIC NER VE 



Dura mater of cord 



^ POSTERIOR PRIMARY 

 DITISIOS 



' GENI TO-CRURAL 



CAUDA EQUINA 



Filum terminale 



EXTERNAL 

 CUTANEOUS 



OBTURATOR 

 LVMBO-SACRAL CORD 



FIRST SACRAL 

 NER VE 



— FIFTH SACRAL 

 NERVE 



— VISCERAL BRANCHES 

 Sciatic artery 

 Sman saero-seiatic 



ligament 

 PUDIC NERVE 



NERVE TO 

 OBTURATOR 

 INTERNUS 



PER FOR A TING 

 CUTANEOUS OF 

 SECOND AND 

 THIRD SACRAL 

 NER VES 



the scrotum. In the female it is distrilnited in a similar manner to the lalnum 

 majus. 



7. The nerve to the obturator internus arises from the front of the 

 plexus from tbc fifth luml)ar and the first :ind second sacral nerves. It passes 

 through the great sacro-sciatic foramen, below the pyriformis, and crosses the base 

 of the ischial si)ine, Ixnng placed on the outer side of the pudic vessels. Having 

 furnished a twig to the superior gemellus, it enters the lesser sacro-sciatic foramen, 

 and ends in the obturator internus. 



8. The perforating cutaneous nerve rises from the second and third sacral 

 nerves. It runs in the angular interval between the great and lesser sacro-sciatic 



