The human vas deferens structure includes the testes, epididymis, vas deferens, ejaculatory ducts, and urethra, with fluid secreted by the prostate, seminal vesicles, and urethral bulbourethral glands involved in the formation of semen. The testes are located in the scrotum, one on each side, and are the site of sperm production. After sperm production, they enter the epididymis from the testicular output tubules through the upper posterior part of the testis. The epididymis temporarily stores sperm, and the epididymal fluid it produces also nourishes the sperm and promotes their maturation. The epididymal ducts continue into the vas deferens, which pass through the spermatic cords on both sides, behind the base of the bladder and before the rectum, through the prostate gland, and join with the output ducts of the seminal vesicles to form the ejaculatory ducts. The ejaculatory ducts pass forward and down through the parenchyma of the prostate and open into the prostatic portion of the urethra, and eventually semen can be discharged through the external urethral opening. Semen contains not only spermatozoa, but fluids secreted by the prostate, seminal vesicles, and urethral bulbourethral glands are also involved in the formation of semen. To summarize, if there is a reproductive system disease, you should seek medical treatment in time.