 Hey everybody, Dr. O here. So we just got done talking about the seminiferous tubules, where that's where immature sperm are produced. Then they're moved to the epididymis. So now we're going to talk about the epididymis. So the spermatozoa, this immature spermatozoa plus some testicular fluid is carried into the epididymis just so you know. Ends up being about 5% of semen is what's coming from the testicles here. So the epididymis is tightly coiled. As you can see here, it's about 20 feet long, so there's one in each testicle or one in each scrotum, sorry, and notice they are in the scrotum. So if a man has a swollen scrotum, it's often epididymitis or an inflammation of the epididymis, not the testicle itself. So they share the scrotum with the testes there. So it's a 20 foot tightly coiled tube surrounding each of these testes. Takes about 12 days for this immature sperm to move from the head of the epididymis all the way through the epididymis to the vas deferens or ductus deferens. So it enters from the semeniferous tubules, it enters through these actual, these efferent ductules into the head of the epididymis. Sperm cannot move on their own at this point, they're very immature. So smooth muscle contractions are what are carrying this sperm from the head to then we have the tail of the body and the tail of the epididymis. So it's going to be slowly carried there. Now as sperm is traveling through the epididymis though, it is starting to mature. So throughout this process, it will pick up the ability to move some. So it'll start to help. But at the beginning it is smooth muscle contraction primarily and maybe some ciliated cells that are carrying this immature sperm. Think about a boat that's been produced but doesn't have a motor put on it yet. So it's going to be carried through the epididymis. So as it's maturing though, it'll pick up the ability to move. Why is that important? Once this sperm reaches the female reproductive tract, it's going to need to move on its own to travel through the female reproductive tract and get to the uterine or fallopian tubes where fertilization will occur. Where will then the sperm is going to be stored here in the tail of the epididymis in telogaculation and then everything's going to move forward and it will be replaced by new sperm being produced behind it. All right. So that's pretty straightforward. That is the epididymis. Next we will see that the epididymis is going to carry sperm to the vas deferens or ductus deferens. So that'll be our next video. I hope this helps. Have a wonderful day. Be blessed.