Topography. 



83 



424. Topography of the Male Perinaeum. III. 



View after removal of the contents of the Cavum iscliio-rectale. 



The perinaeum is the space between the anus and scrotum in 

 the male and between the anus and posterior commissure in the female. 

 The male perinaeum is longer than the female. 



The muscles of the perinaeum are: 



a) M. ischio-cavernosus s. erector penis (see Fig. 425 and 426) covers 

 the unattached part of the crus penis; it arises from the tuberosity of 

 the ischium, behind the crus penis, whence its fibres are directed forwards 

 to an aponeurosis which is inserted into the sides and under surface of the 

 crus penis ; sometimes it joins its fellow on the other side in a median 

 aponeurosis. 



b) M. bulbo-cavernosus s. accelerator urinae (see Fig. 425 and 426) 

 lies upon the Bulbus urethrae, and is connected with the M. sphincter ani 

 externus and the M. transversus perinei superficialis ; it consists of two sym- 

 metrical halves, which arise from the Raphe bulbi. Its fibres encircle 

 the bulb, and are inserted into the fibrous covering of the Corpora caver- 

 no sa penis. 



11* 



