The commencement of the urethra is situ ated within the pelvis, behind the symphysis pubis, to which it is suspended by the appa ratus which supports the neck of the blad der : its next division is directly beneath the inferior pubic ligament, and is connected to it by condensed cellular membrane : the last portion of the urethra passes between the origins of the crura clitoridis, and terminates by a rounded aperture at the anterior part of the vagina, and a little in front of the pubic arch : this aperture is called the meatus urinarius.
The female urethra is invested by a muscu lar apparatus, analogous to that surrounding the membranous portion of the male canal : thus Santorius described some tranverse and circular fibres connected with this part, the latter being situated deepest, and the former passing over the canal, and termed by him " the depressor zerethr." So also often ver tical fibres can be distinguished arising from the back of the symphysis pubis, and analo gous to Wilson's Muscles, in the male. Guthrie* also has given a representation of a muscle arising from the rami of the pubis, and splitting into an upper and under part, and thus completely surrounding the tube, as the muscle known by the name of " Guthrie's muscle" does in the male : this apparatus in the female can only have the effect of effect ually closing the canal. The length of the fe male urethra varies from an inch and a half to two inches; but its diameter is considerably greater than that of the male urethra : thus at its commencement, at the neck of the bladder, it is nearly half an inch in diameter, but it is nearly cylindrical in the remainder of its course, and does not exceed three or four lines in diameter. It is contracted at the meatus urinarius. There are few points of higher practical importance in reference to the surgery of the urinary organs of the female than the extreme dilatability of the urethra. It is well understood that, by the introduction of sponged tents or other mechanical contriv ances, gradually increased in diameter, this canal may be so far dilated as readily to per mit the extraction of urinary calculi of at least an inch and a half in diameter ; and hence the operation of lithotorny is almost superseded by the more simple procedure of extracting the stone by dilatation.
The orifice of the urethra or nzeatus urin arius is situated above and in front of the entrance of the vagina, at the further end of the vestibulum, between the nymphm, and anterior to the hymen in the virgin : it is placed at the distance of an inch from the clitoris. To the eye it presents the appear ance of a closed circular aperture, slightly raised and thickened at its under edge, with a depression in its centre. Without ocular in
spection, it may be found by carrying the fore finger below the clitoris, down along the sym physis pubis for a short distance, when it can be distinguished by its forming a soft semi circular projection, and its corresponding de pression can be readily felt. Under examina tion with the finger the projection of the mea tus increases as if by erection, and thus at once becomes more perceptible to the touch : the inferior lip of the meatus is continuous with the anterior mesian column of the va gina, and contains within it some large mucous crypts ; this was formerly termed the corpus glandulosum. In order to avoid touching the clitoris, which, as a matter of delicacy, is of no slight importance, the meatus may be easily found without exposure, by carrying the finger into the vagina, along the anterior wall of which an elongated spongy swelling will be perceived ; by advancing the finger along this swelling the meatus may be readily reached.
If the urethra be laid open, its mucous membrane is seen thrown into longitudinal plicm, with vallecul or depressions between them. Some of the plicm are larger than the rest : there is usually one large fold along the posterior wall of the canal, and one on either side ; the fold at the back part, after passing for a short distance, generally divides into two branches : it has been compared to the caput gallinaginis in the male. Besides these there are other folds, which, when the urethra is closed, dove-tail into corresponding depres sions. The mucous membrane is of a rosy tint at the meatus, but becomes paler towards the bladder : it is copiously supplied with mucous follicles. These open generally in the depres sions between the rugm ; but there are some large depressions or crypts, into which nu merous smaller follicles open, situated just within the meatus : these equal in size the blunt end of and ordinary probe ; they are imbedded in the under labium of the meatus, and, forming a considerable projection, consti tute the corpus glandulosum of some authors. So also, in the vicinity of the commencement of the urethra, there is a collection of large lacuna visible : indeed the under part of the mucous membrane is at this part studded with small orifices of mucous crypts. These are evidently different from the ordinary lacunte of the urethra: the latter are analogous to those of the male canal, and, being situated between the longitudinal plicm, open obliquely forwards. They are the seat of a copious mucous secretion.