Urology is the field of medicine that focuses on the urinary tracts of males and females, and on the reproductive system of males. In men, the urinary system overlaps with the reproductive system, and in women the urinary tract opens into the vulva. In both sexes, the urinary and reproductive tracts are close together, and disorders of one often affect the other. The organs covered by urology include the kidneys, ureters, urinary bladder, urethra, and the male reproductive organs (testes, epididymis, vas deferens, seminal vesicles, prostate and penis).