urethra

(u-re’thrah) (Gr. οὐρήθρα]. A membranous canal conveying urine from the bladder to the surface, and in the male conveying the seminal ejaculations. The male urethra extends from the neck of the bladder to the urinary meatus, measures 8 or g inches in length, and presents a double curve when the penis is flaccid. It is divided into three portions—the prostatic, the ς membranous, and the spongy. The prostalic portion runs from the base to the apex of the rostate gland; it is the largest portion of the canal in diameter, and 14 inches long. In its floor is a ridge, the terumontanum, or caput gall in agin is. On each side is a fo a, its floor showing the many openings of the prostatic ducts, called the prostatic sinus. The sinus pocularis isa depre ion beneath the middle lobe of the prostate, and in this or on its edges open the ejaculatory ducts. The membranous urethra is the smallest in diameter of any portion of the canal. It runs from the apex of the prostate to the bulb of the corpus spongiosum, being included between the layers of the triangular ligament. It is 14 inches in length. The spongy portion (or penile urethra), about 6 inches long, runs from the membranous portion to the meatus. It has a dilatation posteriorly and one anteriorly—the fo a navicular is. The ducts of Cowper's glands empty into the bulb. The Jacuna magna is a mucous crypt in the roof of the vesicular fo a. The meatus is the anterior urethral orifice: it is a vertical slit, and is the narrowest part of the urethra. The female urethra is 1} inches long; it runs above the anterior vaginal wall, and pierces the triangular ligaments, as in the male. Its structure is similar to that of the male urethra.