Urology Urology is the medical speciality concerned with surgical conditions in the urinary tract and the male reproductive system. The urinary tract comprises the kidneys, the ureters, the bladder, the prostate (in men only) and the urethra. Although men seek urologists more often than women (due to prostate or urethral problems), women with urological problems are usually also treated by urologists. The urinary tract comprises the kidneys, the ureters, the bladder, the prostate (in men only) and the urethra. The kidneys are a paired organ, situated in the flank, one on either side. The kidneys are bean-shaped (although some beans are described as kidney shaped), and approximately 3x6x12 cm of size. The kidneys’ main function is to filter waste products from the blood, and thus form urine. The urine is collected in the kidney pelvis, which continues to form the ureters – two long and narrow tubes leading the urine from the kidneys into the bladder. The bladder serves as a resevoir for the urine, and urine is held back until voiding is necessary and practical. Voiding is initiated by the voiding reflex, which in turn is initiated by the filling of the bladder, usually when the bladder holds 500mL of urine. The bladder is a muscular organ, shaped much like a ballon. During voiding, the passage upwards through the ureters is closed and the passage outwards is opened. Then, the muscles of the bladder contract, and the urine is expelled. If there is a bladder outlet obstruction, voluntary use of the abdominal muscles may be needed to empty the bladder. Finally, the urine is lead out through the urethra. In men the urethra is much longer than in women.