THE FEMALE PERINEUM. 



2049 



The presence of the urogenital cleft prevents the fusion not only of the vestibular 

 hemibulbs (the homologues of the halves of the corpus spongiosum), but also of the 

 bulbo-cavernosus muscles, which, therefore, are present in the female as separate 

 bands that encircle the vestibule. 



The bulbo-cavernosus muscle, often called the sphincter vagina, arises from the 

 perineal centre, blending with the fibres of the external sphincter and the transverse 

 perineal muscles, and divides into a median and a lateral portion as it passes forward. 

 The lateral and more superficial strand encircles the vagina, crosses the crus to gain 

 the dorsum clitoridis, and ends, with the tendon of the opposite muscle, by blending 

 with the fibrous sheath of the clitoris. The median and deeper portion of the muscle 

 (the compressor bulbi of Holl ) partly covers the gland of Bartholin and the vestibular 

 bulb, and in front unites with the corresponding strand of the opposite side in a 



FIG. 1734. 



Clitoris 



Glans of clitoris 



Gluteus 

 maximus 

 Coccygeus 



Vulvar fissure 

 White line of pel- 

 vic fascia slightly 

 displaced toward 

 midline 

 Tuber ischii 



Levator ani 



Anus 



Greater 

 sacro-sciatic 

 ligament 

 -Coccygeus 



Gluteus 

 maximus (cut) 



Coccvx 



Deep dissection of perineum, exposing muscles of pelvic floor. 



delicate tendinous expansion that passes beneath the body of the clitoris and is attached 

 to the crura. 



Between the inferior and superior layers of the triangular ligament is included 

 the deep perineal interspace. In addition to the continuations of the internal pudic 

 vessels and pudic nerves, this interfascial space is occupied by a thin and imperfect 

 muscular sheet that corresponds with the compressor urethrae. The posterior part 

 of this sheet is differentiated, with variable distinctness, into the deep transverse 

 perineal muscles which, arising from the ischial tuberosities, pass behind the vagina 

 to the perineal centre. The remaining part of the sheet, collectively much less 

 developed than the sphincter-like compressor urethrae in the male, is continued 

 forward from the perineal centre as a thin stratum that closely encircles the vagina, 

 and in front either surrounds the urethra or passes in front of the urethra in the 

 interval between the latter and the transverse ligament (Kalischer). In recognition 

 of its relations to both the vaginal and urethral canals, this muscular sheet has been 

 appropriately called the urogenital sphincter. 



129 



