What is Urethra?
[[File:Female and Male Urethra.jpg|thumb|Female urethra and male urethra]] The '''urethra''' is a [[tube]] that connects the [[bladder]] to the outside of the body. All [[Mammal|mammals]] have it. It allows the removal of [[urine]] from the [[body]]. There is a muscle (the ''urethral sphincter'') which controls [[urinating|urination]]. In [[male]] mammals, the urethra is also a part of the [[reproductive system]], because males use it as a tube for [[sperm]] during [[sex]]. == Human anatomy == [[File:Anatomytool Male and female urinary tract English.jpg|thumb|Human male and female urinary bladders and urethras]] In human [[anatomy]], men have longer urethras than women. This means that women have bladder [[infection]]s more often because their bladders are closer to the outside. Because the male urethra is longer and is not straight, [[wikt:insert|inserting]] a [[catheter]] (tube to help urination) is more difficult in men. [[File:Vagina vulva drawing with pointers and numbers.jpg|thumb|right|300px|Detailed view of a human vulva (with anatomical features described): 1 - Clitoral Hood, 2. Clitoris, 3. Labia majora, 4. '''Urinary opening''', 5. Labia minora, 6. Anus, 7. Vaginal opening, 8. Perineum ]] In women, the urethra is 3-4 cm (1.5 in) long. It's opening to the outside of the body is part of the [[vulva]] (the area between a woman's legs). The female urethra is between the [[clitoris]] and the opening to the [[vagina]]. Men's urethra goes through their penis, but in women, it is not in the clitoris. [[File:gray1142.png|thumb|160px|A male urethra cut open along on all its length with urinary bladder and penis structure]] In men, the urethra is about 20 cm (8 in) long and its opening to the outside of the body is at the end of the [[penis]]. The male urethra has three sections: *The ''prostatic'' urethra crosses the [[prostate gland]]. The [[vas deferens]] also opens into the urethra in this section. *The ''membranous'' urethra is a short section that goes through the urethral sphincter. It is 1 or 2 cm lon