1260 



UROGENITAL SYSTEM 



piniform plexus; (4) the testicular lymphatics; and (5) the internal spermatic 

 plexus of nerves from the hypogastric plexus; and (6) branches of the genito- 

 femoral nerve for the supply of the external cremaster muscles. 



3. The Penis 



The penis is composed of three rod-hke bodies composed of erectile tissue 

 (fig. 1023), firmly united together and invested by fascia and integument (fig. 

 1022). When this erectile tissue becomes engorged with blood the organ assumes 

 an erect position, but otherwise it is pendulous, hanging downward in front of the 

 scrotum from its attachment to the symphysis pubis. The erectile bodies are, 

 however, prolonged backward beyond the symphysis pubis into the perineal re- 

 gion, and it is customary to speak of this perineal portion as the root of the penis 

 [radix penis] or pars fixa in contrast to the body of the penis [corpus penis] or pars 

 libera. 



The body of the penis in its flaccid condition is almost cylindrical, but in 

 erection it becomes somewhat triangular in section, what was the anterior surface 

 or dorsum penis* becoming flattened, while the opposite one, the urethral surface 

 [facies urethralis], becomes more sharply rounded. At the free extremity of the 

 penis there is a blunt conical enlargement, the glans penis (fig. 1023), at the apex 

 of which is the external orifice of the urethra. The glans is separated from the 

 body by a constriction, the neck [coUum glandis], and from this region a fold of 

 integument arises, which more or less completely encloses the glans, forming the 

 prepuce [prseputium] (fig. 1024). The prepuce is quite free from the glans 

 dorsally but in the ventral mid-line it is attached to it, almost to the urethral 



Fig. 1022. — Transverse Section through the Body of the Penis. 



Dorsal artery 



Superficial dorsal vein of penis 

 /Deep dorsal vein 



Tunica albuginea 



Vessels 



Tunica albuginea 



Skin 

 Dartos 

 -Septum 

 Corpus cavernosum penis 



Fascia penis 



Artery 

 Artery 



Urethra 

 Corpus cavernosum urethrse 



orifice, by a narrow line of adhesion, the frenulum [frenulum prseputii], which 

 contains blood-vessels of considerable size. The base of the glans has a well- 

 marked rounded border, the corona [corona glandis], and is deeply concave for the 

 reception of the distal ends of the corpora cavernosa penis. 



The integument of the penis is continuous with that of the scrotum and Uke 

 it is pigmented and contains no fat. Immediately below it there is a layer of non- 

 striated muscular tissue, the darios, and beneath this a layer of loose connective 

 tissue, containing the superficial vessels and nerves of the penis; beneath this 

 again is a denser, elastic sheet of connective tissue, the fascia penis (fig. 1022), 

 which encloses the erectile bodies as far as the base of the glans and is continuous 

 with the superficial fascia of the perineum and inguinal region. Where it passes 

 beneath the symphysis pubis it receives from the anterior surface of the latter a 

 strong band of fibrous tissue, which forms the suspensory ligament of the penis 

 [lig. suspensorium penis]. 



Two of the erectile bodies of the penis, the corpora cavernosa penis, are paired 

 (fig. 1023). They are attached at their proximal ends to the base of the tuberosity 

 of the ischium, and in this part of their extent are termed the crura penis, being 



* It should bo noted that the terms "donsum" and "dorsal" are used for the penis in a 

 sense directly opposite their usual meaning. 



