Now that you know all of the moving parts, how do you get the sperm to the egg and make a baby? (No! Don’t stop reading. We’re not going to do the when-mommy-and-daddy-really-love-each-other-thing.) Simply put, when the man’s penis becomes filled with blood through stimulation, it becomes erect and will then be firm enough to be inserted into a woman’s vagina. (Are you rolling your eyes, laughing or ready to pass out yet? We’re not. It’s science. This is just the way it goes… so on we go…)

Next, the semen is signaled to begin its path and, upon ejaculation (release of the sperm-filled semen), 300 million sperm cells will be released into the woman’s vagina whereupon the sperm will swim with speed and hardly any accuracy toward their goal—which is finding that egg! When egg and sperm meet “fertilization” takes place and the embryo (the first cells of the baby) begins to grow.

So those are the facts. Or at least the facts that most schools would be required to teach. But everybody always skips over the part that you want to know about, and well, we won’t. So if you are feeling way wigged out or embarrassed you might want to take a deep breath. You’re not done.

So to begin, what exactly did the word stimulation mean above in the first paragraph, you might ask? Stimulation means to rouse something to action and so yes, in this case it’s pretty literal!! Stimulation of the penis can either be physical or mental. That means it can become erect either through touch or through thoughts alone. In fact, during the teen years, sometimes a penis will become erect at the most inconvenient times for hardly any reason at all. But, in general, over time, men develop more control over their ability to have erections.

Now, just what did we mean by ejaculation? First, go ahead and say it three times fast to get yourself more comfortable. Ok, good. Now, here it is, ejaculation occurs when a man has an orgasm. It begins with stimulation. Stimulation of the penis and genital regions feels good (that’s part of the reason people want to have sex!). It feels good. The good feeling builds and builds until an orgasm occurs—for a man this means a rush of intense pleasure coupled with ejaculation.

Women have orgasms too—also created by the stimulation of the genital regions, especially the clitoris (it’s in the diagram in the last sub-post in case you are wondering where it is). However, a woman’s orgasm does not release her sex cell (the egg) like a male’s orgasm does. In addition, typically, a man will need some “down time” (bad joke we know) before being able to ejaculate again whereas some women can have multiple orgasms (several pleasurable releases) in a relatively short period of time.

Okay, back to the required reading in the next post, where we join the journey those sperm are taking toward that egg….