And now the sperm cells can travel along the lumen of the seminar philosophy tubule and eventually they end up in the epididymus. And once inside the epididymus this is where they mature into sperm cells that look like this. And this is also where our sperm cells are stored before they're released the outside environment. So in the epididymus the sperm cells not only mature into cells that look like this but the epididymis also serves to store those sperm cells before being released to the outside environment. Now let's take a look at the structure of the mature sperm cell. So we have a head, we have a midsection and we have a tail.