FASCLE AND MUSCLES. 



Fascice and Muscles of Perineum. 



Superficial Fascia. This is continuous with adjacent su- 

 perficial fasciae and is prolonged onto the penis and scrotum; 

 on the penis it is not fatty; on the scrotum it is intermingled 

 with involuntary muscle fibres (Dartos muscle) and also forms 

 an incomplete septum between the testicles. In the female it 

 is fatty and helps form the mons veneris and labia majora. 

 Over the posterior part of the perineum it fills the ischio-rectal 

 fossae, forming adipose pads. [434] 



Over the anterior part of the perineum it is divisible into a 

 superficial fatty layer continuous with the same layer in the 

 thigh, and the ischio-rectal fatty pads ; and into a deeper mem- 

 branous layer (Colics') which is attached to the pubic arch, the 

 base of the triangular ligament, and, by a median raphe con- 

 tinuous with that of the scrotum, the root of the penis. An- 

 teriorly it is continued over the spermatic cords to the anterior 

 abdominal wall. The central tendinous point of the perineum 

 lies over the base of the triangular ligament. [435] 



The deep fascia is practically non-existent. 



Sphincter Ani Externus. This is a flattened muscle sur- 

 rounding the anus and divisible into three layers, viz. : Most 

 superficial lamina; subcutaneous fibres decussating in front of 

 and behind anus, without bony attachment. Sphincter ani 

 snperficialis (the main part) ; attached behind to coccyx, and in 

 front to central point of perineum. Deep fibres; a complete 

 sphincter for the canal, continuous with the Levator ani and 

 blending with the Transversus perinei and central point of 

 perineum. [435] 



Corrugator Cutis Ani. Fibres radiating from anus, super- 

 ficial to preceding. [436] 



Transversus Perinei Superficial (inconstant) . Origin ; as- 

 cending ramus of ischium and fascia over it; base of triangu- 

 lar ligament. Insertion; central point of perineum. [436] 



Bulbo-cavernosus. Origin; central point of perineum, 



[195] 



