 Hi everybody, Dr. O'Neill here. Let's go ahead and do a quick overview of the male reproductive system. So first here we see the penis. Let's talk about the primary functions of the male reproductive system are to produce sperm and to get that sperm to the female reproductive tract. So the penis and the scrotum and are going to be your external genitalia. So the penis's job is to deliver that semen once it's been produced. So we'll look at all the internal structures here as well. So we'll talk about the penis in a separate video, but that's the penis's primary job is used for copulation. Obviously it's used for micturition and urination as well. The testicles, so the testes, they have two primary jobs. Number one, they do produce the sperm that makes it into semen, but they also produce your androgens, your male sex hormones. So primarily when you hear the word androgens, think testosterone. There are other androgens, but that's the key one that we talk about. So we'll cover the testes in detail later too, but just think they're making the sperm and they're making the androgens like testosterone. Then you see the actual, let's go to a little closer image here. Then we look at all the other pieces. So we have, if the penis's job is to deliver the semen and the testicles job is to produce the sperm that ends up in the semen. So what all happens in between there? So we have the male reproductive tract, which I'll walk you through right now. And then we have the accessory glands that produce the rest of semen. Semen is only 5% sperm. The rest is this seminal fluids. So we start with the testes. Inside the testes, we have what are called the seminephorist tubules. That's where sperm is being born and starts to mature. Then it travels to the epididymis that you see is still in the scrotum. So if a man has a swollen scrotum, it's often the epididymis that's inflamed, not the testicle itself. So the epididymis is where sperm slowly matures and also where sperm can be stored for months in a state of stasis before it actually moves on. So we go the seminephorist tubules inside the testes to the epididymis, to the vast deference, which they now call the ductus deference. But I think it's important to know both terms. That's going to be the actual tube that travels up the spermatic cord and carries the sperm into the abdominal cavity. So everything's happened outside of the body at this point. Now it's moving into the abdominal pelvic cavity. So that's the job of the vast deference or ductus deference. That's called a vasectomy because here's where they would clip and then singe the ends of this tube that they were trying to make a man sterile so they couldn't produce any more offspring. So that's going to be the ductus or vast deference. Then we travel around where the vast deference meets up with the ducts from the seminal vesicles. You're going to see a little tiny ejaculatory duct and that's going to carry. And now the accessory glands we'll talk about in just a moment, they're going to be adding their secretions to what's now going to be called semen. So it goes ductus deference to the ejaculatory duct and now we're at the urethra. And the urethra has three parts, the prostatic urethra, which travels through the prostate gland. That leads to a lot of problems because a swollen prostate gland will pinch on your urethra. It'd be nice if the prostate gland was off to the side like most glands, but the prostatic urethra, then we have the membranous urethra, which actually travels through the urogenital diaphragm, a little muscle there. If you're doing kegel exercises, you're actually pinching off the urethra at that point. And then we have the spongy or penile urethra that's going to deliver the semen to the femoreproductive tract. So that's going to be the actual path itself. One more time through because it's very important. So the testes or the semen efforts, two rules inside of them, to the epididymis, to the ductus deference, to the little tiny ejaculatory duct. And then now we're at the urethra, the prostatic urethra, membranous urethra, and then the spongy or penile urethra. That's the entire male reproductive tract. Then we have the accessory organs or accessory glands that are making up that 95% of the semen. Most important one is going to be the seminal vesicles. They produce about 60% of the volume of semen. We'll cover them in more detail later, but they produce food for the sperm, primarily fructose. Then you have the prostate gland, which produces about 30% of this seminal fluid. It's going to help maybe buffer some of the fluid as it travels through. There's also an antibiotic in there called seminal plasmid. But most of the functions of the prostate gland are kind of unknown. And then you have those little bubble urethra glands. They're going to lubricate the head of the penis, and they're also going to neutralize the acids that are in the urethra. Because remember, your urine can be acidic, and the urethra is being shared by your urinary system and your reproductive system. So that's the actual tract, and that's going to be the accessory structures as well. So we covered the extra genitalia, and we did a walk to the, not the GI, the male reproductive tract and the accessory glands. I think that's going to be plenty for right now. So let's talk about semen. I forgot I wanted to add this video as well. So the job of the male reproductive system is to produce semen. So what is it? A typical ejaculate's going to have between two and five milliliters of semen in it. Obviously some big variation there. If you're going to take a semen sample to see if there's anything wrong with semen, the man needs to wait 36 hours or have 36 hours of abstinence before you collect a sample. In that ejaculate, you're typically going to see between 20 million to 100 million sperm at a zoa per milliliter. So obviously there's a pretty big variation there. It means one man could have 40 million sperm. The other could have what we say 500 million sperm in a single ejaculate. So a huge difference. Only 5% of that semen is sperm. But you see those, let's say you're at, you need to be probably around 300 million to be able to reproduce. I'm not saying that you can't reproduce at lower numbers, but that's generally a good number to shoot for. About 300 million sperm, why do you need so many? Because if your sperm count is too low, you're going to lose a huge majority of the sperm on the way through their female reproductive system. So only maybe, if you're lucky, 1,000 will make it to their destination. And those 1,500 have to make sure that egg gets fertilized. And it isn't like this picture here. It's not one sperm fertilizing one egg. It takes hundreds of sperm to break down the outside of the egg so one can finally get in and share its genetic payload there. So that's going to be sperm. So sperm is that 5% of semen. The rest of it is seminal fluid. And I've already mentioned that about 60% of that is going to come from the seminal vesicles, 30% was going to come from the prostate gland. And then about 5% from the bulbul urethral glands. And then the other 5% would be what came from the testicles, primarily sperm. So we've already covered the rest of semen as well. But when we get to the accessory glands, I'll talk about what each of those fluids do. Okay, so that's a quick walkthrough of the male reproductive system and then that's semen. I hope this helps. Have a wonderful day, be blessed.