574 



PRACTICAL ANATOMY. 



greater sacro-sciatic ligament, and then cut the latter. You will then see the 

 internal pudics all entering Alcock's canal. (Fig. 258.) 



Branches and Course of Internal Pudic Nerve. A branch of the sacral 

 plexus. (Fig. 194.) The nerve escapes from the pelvis by the greater sacro- 

 sciatic foramen, crosses the spine of the ischium, enters the pelvis by the lesser 

 sacro-sciatic foramen (Fig. 226), above the tendon of the obturator internus 

 muscle, traverses a delamination of the obturator fascia, called Alcock's canal, in 



Gluteua mediun 



Gluteus minimus 



Pyriformis, divided 



into two by the 



great sciatic nerve 



GREAT TROCHANTER 



Obturator externus 



Quadratus femoris 



Fascial insertion of 

 gluteus maximuB 



Horizontal fibres of 

 adductor magnus 



Fleshy insertion of 

 gluteus maximus 



GREAT SACRO-SCIATIC 

 FORAMEN 



OLUTEAL NERVE 

 SUPPLYING POR- 

 TIONS OF GLU- 

 TEUS MEDIVS 



Gluteus maximus 



Obturator Internua. 

 Below is the infe- 

 rior gemellus. The 

 superior gemellus 

 is absent 



BRANCHES Of Iff. 



l-'KllUlU 1'1'llEX- 

 DAL SJERVJi 



GREAT SCIATIC NERVE. 

 I'nder it, oblique fibres of 

 adductor luaguus are setu 



SMALL SCIATIC NERVS 



FIG. 260. DEEP DISSECTION OF THE GLI'TEAL REGION. 

 (From a preparation in the Hunterian Museum.) 



the outer wall of the ischio-rectal fossa. It gives off the following branches : 

 (i) The inferior hamorrhoidal, which crosses the ischio-rectal fossa and supplies 

 the skin around the anus ; (2) the perinea!, which supplies the integument of 

 the scrotum and the labia majora, the transversus perintei, the accelerator urinas, 

 the erector penis, and the compressor urethrae, or deep internal transversus perinaei 

 muscle ; (3) the dorsal ncrcc of tlic penis, which gives off branches to the skin 

 of the penis, and to the corpus cavernosum. 



