858 A MANUAL OF ANATOMY 



cularis is about J inch. At the meatus urinarius the cahbre of the 

 canal is diminished, this being the narrowest part of the entire 

 canal. The spongy portion at its commencement is directed for- 

 wards for a short distance, and then bends downwards. It thus 

 describes a curve, which is situated about 2 inches from its com- 

 mencement, the concavity being directed downwards. This curve 

 is fixed, and corresponds with the angle of the penis, the situation 

 of which is immediately in front of the penile attachment of. the 

 suspensory ligament, where drooping of the organ takes place. 

 Another curve, but of a temporary nature, can be produced by 

 raising the penis towards the abdomen, as in catheterization. The 

 walls of the spongy part of the urethra are in contact, except 

 during the passage of fluid. A transverse section of it, except in 

 the glans, presents a transverse slit with anterior and posterior lips. 

 In the glans, however, the slit is vertical with its lips laterally 

 disposed. At the upper end of the fossa navicularis — that is, the 

 end most remote from the meatus urinarius — the vertical slit is 

 modified by the addition of a short transverse slit, and so presents 

 the shape of an inverted T, as follows, ±. 



Structure. — ^The mucous membrane of the spongy portion is 

 provided with elastic tissue, and is very vascular. It is covered 

 by columnar epithelium, except in the glans, where it is of the 

 stratified squamous variety. Outside the mucous membrane is the 

 submucous coat, which contains two layers of plain muscular tissue 

 — inner longitudinal and outer circular. External to the submucous 

 coat there is a plexus of veins, which forms part of the corpus 

 spongiosum. The mucous membrane contains both simple and 

 compound mucous glands, called the glands of Littre, the openings 

 of the ducts of which are studded over the surface. In addition 

 to these there are other openings, which lead into small blind 

 recesses, called the lacunae of Morgagni, these openings being 

 directed forwards. One lacuna, of large size, called the lacuna 

 magna, or sinus of Giierin, is situated on the roof of the fossa navi- 

 cularis, about I inch from the meatus urinarius. The mucous 

 membrane which surrounds this lacuna is known as the valvule of 

 Guerin. Besides the foregoing openings, the ducts of Cowper's 

 glands open upon the floor of the bulbous portion of the urethra 

 about I inch in front of the antero-inferior layer of the triangular 

 ligament. 



There is sometimes a congenital deficiency in the floor of the 

 spongy urethra, constituting the condition known as hypospadias. 

 In other cases the deficiency may be on the roof, and it is then 

 known as epispadias. 



Lymphatics of the Male Urethra — Penile Portion. — The lymphatic 

 vessels of the penile portion, excluding those of the bulbar part, 

 run from behind forwards, and open into the ring formed by the 

 lymphatics of the glans penis behind the corona glandis. They ulti- 

 mately pass to (i) the pubic group of the inguinal glands, (2) the deep 

 femoral glands, which lie within the crural canal, and {3) the lowest 



