THE FEMALE BLADDER AND URETHRA. 1007 



layer of unstriped muscular fibres, arranged in a circular direction, which sepa- 

 rates the mucous membrane and submucous tissue from the tissue of the corpus 

 spongiosum. 



Surgical Anatomy. The urethra may be ruptured by the patient falling astride of any 

 hard substance and striking his perinseura, so that the urethra is crushed against the pubic arch. 

 Bleeding will at once take place from the urethra, and this, together with the bruising in the 

 peri naeum and the history of the accident, will at once point to the nature of the injury. 



The surgical anatomy of the urethra is of considerable importance in connection with the 

 passage of instruments into the bladder. Otis was the first to point out that the urethra is 

 capable of great dilatability, so that, excepting through the external meatus, an instrument cor- 

 responding to 1 8 English gauge (29 French) can usually be passed without damage. The orifice 

 of the urethra is not so dilatable, and therefore frequently requires slitting. A recognition of 

 this dilatability caused Bigelow to very considerably modify the operation of lithotrity and intro- 

 duce that of litholapaxy. In passing catheters, especially fine ones, the point of the instrument 

 should be kept as far as possible along the upper wall of the canal, as the point is otherwise very 

 liable to enter one of the lacunre. Stricture of the urethra is a disease of very common occur- 

 rence, and is generally situated in the spongy portion of the urethra, most commonly in the 

 bulbous portion, just in front of the membranous urethra, but in a very considerable number of 

 cases in the penile or ante-scrotal part of the canal. 



THE FEMALE BLADDER AND URETHRA. 



The Bladder is situated at the anterior part of the pelvis. It is in relation, in 

 front, with the symphysis pubis ; behind, with the utero-vesical pouch of peritoneum, 

 which separates it from the body of the uterus ; its base lies in contact with the 

 connective tissue in front of the cervix and upper part of the vagina. Laterally, 

 is the recto-vesical fascia. The bladder is said by some anatomists to be larger in 

 the female than in the male. At any rate, it does not rise above the symphysis 

 pubis till more distended than in the male, but this is perhaps owing to the more 

 capacious pelvis rather than to its being of actually larger size. 



THE URETHRA. 



The Urethra is a narrow membranous canal, about an inch and a half in 

 length, extending from the neck of the bladder to the meatus urinarius. It is 

 placed beneath the symphysis pubis, imbedded in the anterior wall of the vagina ; 

 and its direction is obliquely downward and forward, its course being slightly 

 curved, the concavity directed forward and upward. Its diameter Avhen undilated 

 is about a quarter of an inch. The urethra perforates the triangular ligament, 

 and its external orifice is situated directly in front of the vaginal opening and 

 about an inch behind the glans clitoridis. 



Structure. The urethra consists of three coats : muscular, erectile, and mucous. 



The muscular coat is continuous with that of the bladder ; it extends the whole 

 length of the tube, and consists of a circular stratum of muscular fibres. In 

 addition to this, between the two layers of the triangular ligament, the female 

 urethra is surrounded by the Compressor urethras, as in the male. 



A thin layer of spongy erectile tissue, containing a plexus of large veins inter- 

 mixed with bundles of unstriped muscular fibre, lies immediately beneath the 

 mucous coat. 



The mucous coat is pale, continuous externally with that of the vulva, and 

 internally with that of the bladder. It is thrown into longitudinal folds, one of 

 which, placed along the floor of the canal, resembles the verumontanum in the 

 male urethra. It is lined by laminated epithelium, which becomes transitional 

 near the bladder. Its external orifice is surrounded by a few mucous follicles. 



The urethra, from not being surrounded by dense resisting structures, as in the male, admits 

 of considerable dilatation, which enables the surgeon to remove with considerable facility calculi 

 or other foreign bodies from the cavity of the bladder. 



