Urethra
Urethra, refers to a duct that transmits urine from the bladder to outside the body of a human during urination. The urethra is usually kept closed by the urethral sphincter,it is a muscular structure that controls the urine in the bladder until voiding can occur.
In males, the urethra is structurally linked with the reproductive structures. It is about 7 to 8 inches long which passes along the length of the penis before emptying. The male urethra can be anatomically divided into three sections, as follows: the prostatic urethra, the membranous urethra, and the spongy urethra.
The female urethra is kept within the vaginal wall, and its opening is located between the labia. The female urethra is much shorter than that of the male, being only 1.5 inches long. It begins at the neck of the bladder and opens to the outside just after passing through the urethral sphincter.