The testes are where sperm are manufactured in the scrotum. The epididymis is a tortuously coiled structure topping the testis, and it receives immature sperm from the testis and stores it several days. When ejaculation occurs, sperm is forcefully expelled from the tail of the epididymis into the deferent duct. Sperm then travels through the deferent duct through up the spermatic cord into the pelvic cavity, over the ureter to the prostate behind the bladder. Here, the vas deferens joins with the seminal vesicle to form the ejaculatory duct, which passes through the prostate and empties into the urethra. When ejaculation occurs, rhythmic muscle movements propel the sperm forward.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.