THE MALE URETHRA 



497 



the penis lies. This tubular cavity is closed behind by the reflection of the internal 

 layer on to the penis to form the penile layer of the prepuce. Its orifice is sur- 

 rounded by a thick margin, the preputial ring (Annulus prseputialis), which is 

 connected ventrall}^ with the outer part of the sheath by the preputial frenum 

 (Frenulum praeputii). 



The arrangement differs from that found in man in the fact that the inner part of the pre- 

 puce as described above is equivalent to the entire human prepuce. Tliis part, the prepuce 

 proper, is well seen on sagittal sections, and can be demonstrated by pulling the penis, inclosed 

 in this prepuce, out of the cavity of the sheath; the arrangement of the free part of the penis and 

 prepuce is then like that in man. (In paraphimosis the penis is strangulated by the preputial 

 ring.) 



Structure. — The external skin of the prepuce resembles that of the scrotum. 

 The inner layers of skin are hairless, variable in color, and often irregularly pig- 

 mented; they form irregular folds, and are supplied with numerous large sebaceous 

 glands and coil glands, which reach their greatest size at the preputial ring. Be- 



lAhdorni hat loczU 



Fig. 397. — Sagittal Section of Prepuce and Part of Penis of Horse. 



P, Internal part of prepuce or prepuce proper; P', external part of prepuce or sheath; c.p., preputial cavity; 



F.fl., fossa glandis; D, diverticulum of fossa glandis; p.u., processus urethras. 



yond this the glands are absent, and the skin resembles a non-glandular mucous 

 membrane. The secretion of the preputial glands (Glandulse prseputiales), to- 

 gether with desquamated epithelial cells, forms the fatty smegma praeputii, which 

 has a strong unpleasant odor, and often accumulates in considerable amount. 

 Beneath the skin is a large amount of loose connective tissue, except over the glans 

 penis, where the skin is closely attached to the tunic of the corpus spongiosum. 

 The external part of the prepuce is strengthened by a layer of elastic tissue, derived 

 from the abdominal tunic, and termed the suspensory ligament. 



Vessels and Nerves. — The arteries are l)ranches of the external pudic artery, 

 and the veins go chiefly to the external pudic vein. The lymphatics go to the super- 

 ficial inguinal and lumbar lymph glands. The nerves are derived from the pudic, 

 ilio-hypogastric, and ilio-inguinal nerves. 



THE MALE URETHRA. 



The urethra of the male (Urethra masculina) is the long mucous tube which 

 extends from the bladder to the glans penis. It passes backward on the floor of 

 32 



