Sperm cells mature in the epididymis, a 20-foot-long series of thin, tightly coiled tubes. Sperm take from two to 12 days to pass through the epididymis and to develop the ability to swim and ...

In men, at puberty when the sperm first appear in the testis and epididymis, the human immune system will have the chance to contact sperm antigens. Similarly, when women become sexually active ...