1250 



SPLANCHNOLOGY 



The extremity is formed by the glans penis, the expanded anterior end of the 

 corpus cavernosum urethrse. It is separated from the body by the constricted 

 neck, which is overhung by the corona glandis. 



The integument covering the penis is remarkable for its thinness, its dark color, 

 its looseness of connection with the deeper parts of the organ, and its absence of 

 adipose tissue. At the root of the penis it is continuous with that over the pubes, 

 scrotum, and perineum. At the neck it leaves the surface and becomes folded 

 upon itself to form the prepuce or foreskin. The internal layer of the prepuce is 

 directly continuous, along the line of the neck, with the integument over the glans. 

 Immediately behind the external urethral orifice it forms a small secondary redu- 

 plication, attached along the bottom of a depressed median raphe, which extends 

 from the meatus to the neck; this fold is termed the frenulum of the prepuce. The 

 integument covering the glans is continuous with the urethral mucous membrane 

 at the orifice; it is devoid of hairs, but projecting from its free surface are a number 

 of small, highly sensitive papillae. Scattered glands on the corona, neck, glans and 

 inner layer of the prepuce, the preputial glands, have been described. 1 They secrete 

 a sebaceous material of very peculiar odor, which probably contains casein, and 

 readily undergoes decomposition; when mixed with discarded epithelial cells it is 

 called smegma. 



The prepuce covers a variable amount of the glans, and is separated from it 

 by a potential sac the preputial sac which presents two shallow fossae, one on 

 either side of the frenulum. 



Structure of the Penis. From the internal surface of the fibrous envelope of the corpora 

 cavernosa penis, as well as from the sides of the septum, numerous bands or cords are given off, 



which cross the interior of these cor- 

 pora cavernosa in all directions, sub- 

 dividing them into a number of sepa- 

 rate compartments, and giving the 

 entire structure a spongy appearance 

 (Fig. 1157). These bands and cords 

 are called trabeculae, and consist of 

 white fibrous tissue, elastic fibers, and 



plain muscular fibers - In them are 

 contained numerous arteries and nerves. 

 The component fibers which form the 

 trabeculae are larger and stronger 

 around the circumference than at the 

 centers of the corpora cavernosa; they 

 are also thicker behind than in front. 

 The interspaces (cavernous spaces), on 

 the contrary, are larger at the center 

 than at the circumference, their long 

 diameters being directed transversely. 

 They are filled with blood, and are 

 lined by a layer of flattened cells sim- 

 ilar to the endothelial lining of veins. 

 The fibrous envelope of the corpus 

 cavernosum urethrse is thinner, whiter 

 in color, and more elastic than that of 

 the corpora cavernosa penis. The trabec- 

 ulae are more delicate, nearly uniform in size, and the meshes between them smaller than in the 

 corpora cavernosa penis: their long diameters, for the most part, corresponding with that of 

 the penis. The external envelope or outer coat of the corpus cavernosum urethrse is formed 

 partly of unstriped muscular fibers, and a layer of the same tissue immediately surrounds the 

 canal of the urethra. 



Vessels and Nerves. The arteries bringing the blood to the cavernous spaces are the deep 

 arteries of the penis and branches from the dorsal arteries of the penis, which perforate the fibrous 

 capsule, along the upper surface, especially near the forepart of the organ. On entering the 



1 Stieda (Comptes-rendus du XII Congress International de M6decine, Moscow, 1897) asserts that glands are never 

 found on the corona glandis, and that what have hitherto been mistaken for glands are really large papillse. 



FIG. 1157. Section of corpus cavernosum penis in a non-dis- 

 tended condition. (Cadiat.) a. Trabeculse of connective tissue, 

 with many _ elastic fibers and bundles of plain muscular tissue, 

 some of which are cut across (c). 6. Blood sinuses. 



