410 A MANUAL OF ANATOMY. 



not constant in man ; it is named, from its action, the com- 

 pressor venae dorsalis penis. 



Nerve Supply. Perineal. 



Action. To compress the dorsal vein of the penis (by 

 the small slip mentioned above) and so produce erection 

 of the penis. The main part of the muscle compresses 

 the crus penis, and so aids erection and maintains the penis 

 erect after it becomes engorged. 



Transversus Perinsei. (Superficial transversus perincei.) 

 Fig. 82. 



Origin. From the inner surface of the tuberosity of the 

 ischium. 



Insertion. Into the tendinous centre of the perineum. 



Nerve Supply. Superficial perineal. 



Action. To fix the tendinous centre, aid in supporting 

 the pelvic floor. 



Accelerator Urinse. (Bulbocavernosus?) Fig. 82. 



Origin. From the median raphe, reaching from the 

 tendinous centre of the perineum forward upon the bulb of 

 the penis to opposite the lower border of the symphysis. 



Insertion. In three portions: (i) A small set of fibres 

 anteriorly, which surround the corpora cavernosa (and, of 

 course, the corpus spongiosum) to be inserted upon the 

 dorsum of the penis above (or over) the dorsal vein of the 

 penis. (2) A middle set, the most of the muscle, which 

 passes forward around the corpus spongiosum (and so be- 

 tween it and the corpora cavernosa) to the dorsum of the 

 corpus spongiosum. (3) A third set posteriorly, also 

 small, which surrounds the bulb of the penis behind the 

 membranous urethra, and is inserted into the dorsum of 

 the bulb and the superficial layer of the triangular ligament 

 close to the exit of the urethra. 



