648 A MANUAL OF ANATOMY 



of the penis. At the root of the organ it passes between the two 

 laminae of the suspensory ligament, and then between the subpubic 

 and transverse perineal or pelvic ligaments. In this part of its 

 course it communicates with the venous plexus in the compressor 

 urethrge muscle in which the internal pudic venae comites arise. On 

 entering the pelvis it divides into two branches, which terminate 

 in the right and left portions of the prostatic plexus of veins. 



In addition to the deep dorsal vein, there are two superficial dorsal veins 

 which take up blood from the glans and integument. Each accompanies a 

 branch of the superiot external pudic artery, and opens into the superior 

 external pudic vein. 



For a description of the dorsal nerves of the penis, see p. 627. 



The relation of the structures on the dorsum of the penis, from 

 the middle line outwards, is as follows: deep dorsal vein, dorsal 

 artery, and dorsal nerve. 



Composition of the Penis. — ^The penis has tv/o surfaces, upper 

 or dorsal and under or scrotal. Viewed as a whole the organ is 

 composed of three cylindrical bodies, namely, two corpora cavernosa 

 and a corpus spongiosum, closely applied to each other. It is 

 divisible into a root, body, cervix, and glans. The root is formed 

 by the crura of the corpora cavernosa, which are attached to the 

 inner margins of the ischio-pubic rami. The upper surface of the 

 root is also connected to the symphysis pubis by the suspensory 

 ligament; The upper or dorsal surface of the body is formed by the 

 corpora cavernosa, the under or scrotal surface being formed by the 

 corpus spongiosum in the middle line and the corpora cavernosa 

 at either side. The corpora cavernosa and corpus spongiosum at 

 their meeting become flattened, and so the shape of the body is 

 subcylindrical. The corpora cavernosa terminate in round ex- 

 tremities, in front of which the corpus spongiosum turns upwards, 

 and, becoming much enlarged, forms the glans penis. The cervix 

 is the constriction between the body and the glans. The glans 

 penis is formed by the corpus spongiosum. It is somewhat conical, 

 and has been likened to an acorn, from which circumstance it has 

 been called the balanus. At the base there is a wheel-like rim, 

 called the corona glandis. The part anterior to the corona is called 

 the body of the glans, and this terminates in a small round tip, 

 which presents a vertical fissure called the nf-aius urinarius. For 

 the structure of the penis, see p. 856. 



Lymphatics. — ^These are divided into a superficial and deep set. 



The superficial lymphatics of the prepuce, having formed 

 a plexus, pass to the cervix, which they surround in the form 

 of a ring. Those of the glans, having also formed a plexus, 

 pass along with those of the spongy portion of the urethra 

 to the foregoing ring. From this ring three lymphatic trunks 

 proceed towards the symphysis pubis. One of these is median and 

 dorsally placed, whilst the other two are disposed one on either side. 

 The median trunk, when it reaches the suspensory ligament of the 

 penis, divides into two branches, right and left. Each of these 

 passes with the corresponding lateral trunk to the groin of the same 



