 All right, I'm going to start drawing you a picture and then I'm quickly going to change tact and you won't get a picture from me. I will have to punt and ask someone else to draw the picture. That would be the open stacks textbook crew. Here are my two kidneys. Here is the tube that is bringing the urine once it's been produced by the kidney. It's bringing the urine away, away with you. So my question is, number one, what's this tube called? It's carrying urine at this point and it's the ureter, ureter, ureter. Okay, that was a good one, huh? Where's the ureter taking the urine to the bladder? So check it out. I have to draw this. I'm going to draw my bladder like this. Here's my bladder and like that. And we'll look at where a bladder is located in the body in just a second. I'm drawing it like this because what I want you to see is that the ureters, there's a place in the bladder where the ureter opens. The dotted line is showing you that the ureter is passing behind the bladder and then there's this little opening. So the, whatever, right side kidney is dumping urine in through this little hole into the bladder. The same thing is true for the left side kidney. It's dumping the urine in through a little hole. So this is like the opening of the ureter. We're dumping urine in. How does urine get out? Well, fancy that you ask such a thing. There is also a hole by which urine leaves the bladder. The ureters bring urine in, urethras bring urine out. Bye-bye. Before I tell you about the phenomenal nature of urethras, I want to tell you this, again, is nothing more than a hole. And so you actually have three holes in a kind of triangular shape in the wall of the bladder and two holes let urine in and one hole lets urine out. And together, if you were to draw a line connecting the holes, because I know that's exactly what you wanted to do, you form a little triangular, like, place in the bladder and that is called the trigone. The trigone is the triangle created by the openings to the ureters and the urethra. Now, I'm not going to attempt to draw this next picture because my skills are only so phenomenal. And the picture, what we have to look at is the urethra, the position of the urethra, and here's the deal. The ladies have a urethra, the fellas have a urethra, everybody needs a urethra to get pee out of their bodies, but our urethras are a lot different. So let's go look at the... Oh, it looks like we have a girl urethra first. How do I know it was a girl urethra? Well, let's orient, shall we? First of all, look, this is a, what? Midsagital slice of femaleness. And what's highlighted in color is the bladder. What you can see right here, this little tube that exits the bladder right about her, that is my urethra. Does that work for you? The urethra has an opening. That's the urethral meatus, the external urethral meatus. I'm sorry if it's a meatus. External urethral orifice, much better than meatus. External urethral orifice, ladies and fellas have this structure. The urethra of female humans is anterior and found between labia majora, and we're going to do reproductive anatomy in the next lecture. So parts and pieces will become more clear, but the labia majora are the big lips, the flaps of skin in the vulva of the external female genitalia. Check it out, just for perspective, I have another hole right here. This is the vagina for perspective, and I have another hole. Oh, but of course, we must have one more. This is the anus. Women have three holes. This is important for you to be aware of. It's different from the fellas. All right, ladies, it's a urethra. We're done. Fellas, not so fast. The urethra actually has three parts in the fellas because, holy crud, it's a lot longer. The urethra in the fellas has two functions. It functions in urine excretion. Here's my bladder, just like we would expect. In the fellas, they had their ureters drawn in. It's kind of nice why we didn't get our ureter drawn in there. That's okay, I'll forgive you. We have the opening to the urethra right here. You can see that, and we also have the external urethral orifice, right here. The urethra is colored, you can see that. Do you think we're going to revisit the fellas urethra when we talk about the reproductive system? But of course, the male urethra is unique because it also carries reproductive swimmers. Those would be our spermies. Our spermies are created in the testes. They travel up through the vas deferens and they get dumped eventually into the urethra. Now, before we go anywhere else, we need to know that the male urethra actually has three parts. Two of them are illustrated nicely here and one of them is sort of missing. First, urethra, it's all one tube. But depending on what structure it's passing through, it gets a new name. I'm going to tell you that this structure right here that I'm coloring in blue, that is the prostate gland. Prostate gland, which is fantastic because you tell me what is the name of the urethra that passes through the prostate gland. I just colored it in and now it looks terrible. Okay, I'll undo that. This, my friends, is the prostatic urethra. It's kind of not a big deal because it's the prostatic urethra until it gets out of the prostate. You're going to have to know the prostate for the reproductive system. So it's actually getting us ahead of the game to have our urethral parts. Now, the piece of urethra that is not very clearly illustrated here is it's called the membranous urethra and I'm going to call it like right here and we'll just say that it's right there and the membranous urethra, okay, I'm going to draw in the part that is missing. The membranous urethra is this little short piece of urethra that passes through the urogenital diaphragm and there's this whole set of pelvic floor muscles that basically keep your guts from falling out of your pelvis hole. Like think about your pelvis. Think about that giant hole in the middle of your pelvis and think about like why don't your guts fall out that thing? Your urogenital diaphragm plays a role. There's actually muscles and other tissues that cover that hole and prevent the stuff from falling out. So urethras have to go through that hole. I mean, urethras have to go through that, yeah, that pelvis hole. If they can't get through, then you can't pee your stuff out. That is the part of the urethra that passes through there is the membranous urethra. After that, everything else in this penis is called the spongy urethra. So everything else, can't see that, is the spongy urethra. It's also called the penile urethra. So if you see that, that is why. Penile urethra makes much more sense to me because I'm cool with spongy urethra as well because what I know and what you will learn in the next lecture is that the urethra that passes through the penis is surrounded by spongy erectile tissue. And it's spongy because it's got all these spaces that can fill with blood. So we'll talk about that aspect, but I want you to know your urethra parts. Once we have our urethra parts, we can make PPs come out of our urinary system. All right. That's gross anatomy. Now we get to go back to the kidney itself and look at the microscopic anatomy that enables the function of the kidney. I will be right back.