256 



DISSECTION OF THE PERINEUM. 



Dissection. 



Take first 

 ischio-rectal 



Then 

 examine 

 anterior 

 half ot 

 perineum. 



Superficial 

 fascia. 



Dartoid 

 tissue. 



Superficial 

 vessels and 

 nerves. 



Dissection 

 of the 

 muscles. 



Sphincter 

 vaginte : 



origin 



Dissection. The steps of the dissection are much the same in 

 both sexes, and the same description will serve, generally, for the 

 male and female perineum. 



First, the dissection of the ischio-rectal fossa is to be made. 

 Afterwards the muscles, vessels and nerves of the posterior half of 

 the perineal space are to be examined. (See description of the 

 male perineum, pp. 237 to 243.) 



Next, the skin is to be taken from the anterior half of the perinea! 

 space, as in the male ; and the transverse incision in front is to be 

 made at the anterior part of the vulva. The attachments of the 



superficial fascia are 

 then to be looked to, 

 and the cutaneous ves- 

 sels and nerves are to 

 l^e traced beneath it 

 (p. 244 et seq.). 



Superficial fascia. 

 The description of this 

 fascia in the male will 

 serve for the like part 

 in the female, with 

 these modifications : 

 that in the female it 

 is interrupted in the 

 middle line, and is of 

 less extent, in conse- 

 quence of the aperture 

 of the vulva ; and that 

 it is continued for- 

 wards through the 

 labia majora to the 

 inguinal region. In 

 the labia the super- 

 ficial fascia contains involuntary muscular fibres, like the dartos tunic 

 of the scrotum, as well as fat. 



The SUPERFICIAL PERINEAL VESSELS and NERVES, and the 

 INFERIOR PUDENDAL NERVE have the same arrangement as in the 

 male (p. 245) ; but they are distributed to the labia instead of to 

 the scrotum. 



Dissection. The labia and the superficial fascia are then to be 

 removed, to follow the sphincter muscle around the opening of the 

 vagina. Two other muscles are exposed at the same time, viz., the 

 erector clitoridis lying along the ramus of the ischium, and the 

 transversus perinei passing across the perineum to the central point. 

 The SPHINCTER VAGINAE (bulbo-cavernosus ; fig. 95, A) is a partially 

 orbicular muscle around the orifice of the vagina, and corresponds to 

 the ejaculator urinae in the male. Posteriorly it is attached to the 

 central point of the perineum, where it blends with the sphincter 

 ani and transversus muscles ; and its fibres are directed forwards on 



FIG. 95. VENOUS PLEXUSES OP THE GENITAL 

 ORGANS, AND OPENING OP THE VAGINA (KOBELT). 



A. Sphincter vaginae muscle. 



B. Clitoris, 

 c. Nympha. 



a. Bulb of the vestibule. 



b. Venous plexus continuous with veins 



of the clitoris. 



c. Dorsal vein of the clitoris. 



