Urinary Burning Anatomy
To better understand painful urination, it helps to understand the anatomy of the bladder and genitourinary tract.
In an adult, the bladder can hold 10 to 20 ounces of urine: about as much liquid as in one can of soda. Urine is carried out of the body through the urethra, a tube at the bottom of the bladder.
As the bladder fills, it pushes against the rest of the organs in the abdomen. Urine empties from the bladder through the urethra. Muscles located in the base of the urethra control the flow of urine. During urination, these muscles relax, and urine is allowed to pass.
- Bent S, Nallamothu BK, Simel DL, Fihn SD, Saint S. Does this woman have an acute uncomplicated urinary tract infection? JAMA. 2002 May 22-29;287(20):2701-10. 
- Bremnor JD, Sadovsky R. Evaluation of dysuria in adults. Am Fam Physician. 2002 Apr 15;65(8):1589-96. 
- Shaikh N, Morone NE, Lopez J, Chianese J, Sangvai S, D'Amico F, Hoberman A, Wald ER. Does this child have a urinary tract infection? JAMA. 2007 Dec 26;298(24):2895-904.