404 



DISSECTION OF THE PELVIS. 



Pudic. 



Perforating 

 cutaneous. 



Branch to 

 pyriformis. 



Branch to 

 obturator 

 internus. 



Branch to 

 quadratus. 



Sympathetic 

 in the pel vis. 



The gan- 

 gliated cord 



joins that 

 of opposite 

 side below 

 in a loop ; 



offsets of 

 the ganglia, 



to the spinal 

 nerves, 



to the pelvic 

 plexus and 

 the viscera. 

 Pelvic 

 plexuses ; 



situation ; 



how formed : 



offsets to 

 the viscera 

 of the male, 

 viz., 



to the 

 rectum : 



thigh, and arises before the foregoing (with which it is often con- 

 nected) from the second and third sacral nerves. 



e. The pudic nerve (p) supplies the perineum and the genital 

 organs. It arises from the third and fourth sacral nerves, and 

 courses over the small sacro-sciatic ligament, in company with its 

 artery, to the small sacro-sciatic foramen. 



/. The perforating cutaneous nerve (pc) arises from the fourth, or 

 the third and fourth, sacral nerves, and passes backwards through 

 the great sacro-sciatic ligament to the skin of the buttock (p. 112). 



g. The branch to the pyriformis (py) is usually given off from the 

 second sacral nerve, and enters the anterior surface of its muscle. 



h. The nerve to the obturator internus (oi) springs from the front 

 of the part of the plexus formed by the union of the lumbo- sacral 

 cord with the first sacral nerve. It leaves the pelvis with the pudic 

 artery, and winding over the ischial spine and through the small 

 sacro-sciatic foramen, enters the perineal surface of the muscle : it 

 gives a branch to the superior gemellus. 



i. The nerve to the quadratus femoris and inferior gemellus (q) 

 arises from the front of the plexus below the preceding. 



SYMPATHETIC NERVE. In the pelvis the sympathetic nerve con- 

 sists of a gangliated cord, and of a plexus on each side. 



The GANGLIATED CORD (fig. 149) lies on the front of the sacrum, 

 internal to the series of apertures in that bone. Inferiorly it con- 

 verges to its fellow, and is united with it by a loop in front of the 

 coccyx, on which there is often a median ganglion (gang, impar). 

 Each cord is marked by ganglia at intervals, the number varying 

 from three to five : from them branches of communication pass 

 outwards to the spinal nerves, and some filaments are directed 

 inwards in front of the sacrum. 



The connecting branches are usually two to each ganglion, grey 

 and white, and are very short. 



The internal branches are small, and communicate around the 

 middle sacral artery with the branches of the opposite side. From 

 the first, or first two ganglia, some filaments are furnished to the pelvic 

 plexus ; and from the terminal loop offsets descend over the coccyx. 



The PELVIC PLEXUSES (lateral inferior hypogastric) are two in 

 number, right and left, and are continuous with the lateral pro- 

 longations of the hypogastric plexus (p. 319). Each is situate by 

 the side of the bladder and rectum in the male, and by the side of 

 the uterus and vagina in the female, and is joined by offsets of the 

 third and fourth sacral nerves. Numerous ganglia are found in 

 the plexus, especially at the points of union of the spinal and 

 sympathetic nerves. 



Offsets. From each plexus offsets are furnished along the 

 branches of the internal iliac artery to the viscera of the pelvis, 

 and the genital organs : these form secondary plexuses, and have 

 the same name as the vessels on which they are placed. 



The inferior hcemorrhoidal plexus is an offset from the back of 

 the plexus to the rectum, and joins the sympathetic on the superior 

 hsemorrhoidal artery. 



