Female urethra is a narrow membranous canal, about 4 cm. long, extending from the internal to the external urethral opening. It is, embedded in the anterior wall of the vagina. The male urethra extends from the internal urethral orifice in the Urinary bladder to the external urethral orifice at the end of the Penis. Urethra presents a double curve in the ordinary relaxed state of the Penis. Its Diameter of female urethra when undilated is about 6 mm Male length varies from 17.5 to 20 cm

The urethra is a canal that carries urine from the bladder. In males it is inside of the Penis and it also carries semen and sperm out of the Penis. In females the urethra only carries urine from the bladder. When you urinate, the Brain signals the bladder muscles to tighten, squeezing urine out of the bladder. At the same time, the Brain signals the sphincter muscles to relax. As these muscles relax, urine exits the bladder through the urethra. When all the signals occur in the correct order, normal urination.

Uretheritis (inflammation of the urethra) Sexually transmitted diseases