Henry Gray (1825–1861). Anatomy of the Human Body. 1918.
3b. 5. The Female Urethra
The female urethra (Fig. 1139) is a narrow membranous canal, about 4 cm. long, extending from the internal to the external urethral orifice. It is placed behind the symphysis pubis, imbedded in the anterior wall of the vagina, and its direction is obliquely downward and forward; it is slightly curved with the concavity directed forward. Its diameter when undilated is about 6 mm. It perforates the fasciæ of the urogenital diaphragm, and its external orifice is situated directly in front of the vaginal opening and about 2.5 cm. behind the glans clitoridis. The lining membrane is thrown into longitudinal folds, one of which, placed along the floor of the canal, is termed the urethral crest. Many small urethral glands open into the urethra.