Urology and genitourinary medicine > Anatomy: male urinary tract

  • The urinary tract is responsible for the production, storage and passing of urine. It includes the kidneys, ureters, bladder and urethra.
  • The two kidneys lie at the back of the abdomen. They produce urine by ‘filtering’ unwanted substances from the blood. The urine produced passes out of the kidneys, down both ureters and into the bladder, where it is stored.
  • The bladder fills with urine over 3–4 hours. As it fills, you become increasingly aware of the need to pass urine. During urination, urine passes from the bladder down the urethra to the outside. This involves simultaneous relaxation of the muscles of the urethra and contraction of the muscle of the bladder.
  • In men, the urinary and genital tracts overlap. Semen is made in the testes (testicles) and passed up two tubes (called the vas deferens) to be stored in the seminal vesicles behind the prostate. At ejaculation, the bladder neck closes and semen passes down the urethra and out through the penis.
  • The prostate is a small gland just below the bladder that fits around the urethra rather like a collar. The prostate produces a fluid that forms part of the semen.
  • In men over 40, the prostate often enlarges gradually and presses on the urethra causing obstruction. This can make it difficult to pass urine and you may be unable to empty your bladder completely. You may also feel the need to pass urine more often and more urgently.