Urination

Urination is the process of disposing urine from the urinary bladder. The process of urination is usually under voluntary control. When control over urination is lost, this is called urinary incontinence.

During urination, muscles in the wall of the bladder contract, forcing urine out of the bladder and into the urethra. At the same time, sphincter muscles surrounding the urethra relax, letting urine pass out of the body. Urinary incontinence will occur if the bladder muscles suddenly contract or muscles surrounding the urethra suddenly relax.

In wealthy countries, humans usually urinate at a toilet (also known euphemistically as a "bathroom"). Public toilets are often separate for men and women. Those for men often have also urinals. These may have partitions between them to avoid men being able to see the penises of other men.

Men's trousers usually have a fly allowing men to urinate without lowering the whole trousers. The fly has buttons[?] or a zipper[?]. Either just the fly is opened or also the fastening at the waist (including, if present, the belt). Additionally, the fly of the underpants is used or their frontside is lowered. All combinations are possible. Trousers without fly, like some jogging trousers, have usually an elastic waist band allowing lowering the front side like underpants.

A novelty, still rare, are public urinals for women, allowing them also to urinate standing up. This is done using a special tool [1] (http://www.travelmateinfo.com/) or with the finger-assist method [2] (http://www.restrooms.org/standing.html).

A common transgression is urinating in the street. Often this is done after consumption of alcoholic beverage: the alcohol causes production of additonal urine as well as a reduction of inhibitions.

In dogs and other animals, urination can mark territory or express submissiveness.