6i6 



A MANUAL OF ANATOMY 



Action. — The muscle compresses the crus penis against the ischio- 

 pubic ramus, and, by retarding the return of venous blood, it helps 

 to maintain the penis in a state of erection. It also contributes to 

 the maintenance of erection by compressing the dorsalis penis vein. 



The anterior and outer part of the muscle is sometimes detached, and 

 forms a separate muscle, called the compressor venae dorsalis penis. This 

 arises from the descending pubic ramus, anterior to the origin of the ischio- 

 cavernosus, and it terminates in an aponeurotic expansion which joins its 

 fellow of the opposite side over the dorsal vein of the penis. 



Ischio-cavernosus 

 Bulbo-cavernosus 



Membranous Urethra 

 (exposed) 



,. Crus Penis 

 . - Bulb (uncovered) 



-- Antero-inferior Layer of 

 Triangular Ligament 



Levator Ani (cut) 



Gluteus Maximus 



Anus 



Fig. 275. — Deep Dissection of the Male Perineum 

 (The rectum has been turned back). 



Bulbo-cavernosus (accelerator or ejaculator urinae) — Origin. — 

 (i) The central tendinous point of the perineum ; and (2) the median 

 raphe, which is continued forwards from that point towards the 

 symphysis pubis. 



Insertion. — ^The muscle, as regards its insertion, is conveniently 

 divided into three parts, namely, the chief part, the anterior part 

 and the posterior part. 



Chief Part. — ^The fibres of this part ascend between the crus penis 

 and the side of the bulb to be inserted into the median raph6 on the 

 upper surface of the bulb, where they meet the fibres of the corre- 

 sponding part of the opposite muscle. 



