 Let's talk about the anatomy of the nephron. There are about a million nephrons inside a single kidney. That should give you a perspective of how small the nephron is. And a nephron is just a tube. It's a crazy, tangled, wildly tangled tube tightly associated with blood in capillaries. So let's draw the tube parts of our nephron first. But don't forget that there are a million of these puppies in a single kidney, so they're small. And that's important to keep in mind. All right. I like to draw my nephrons in orange, the tubular part of a nephron in orange. And I'm going to draw like a little cross section of this thing. It looks like it has a little lobster claw. And that is called Bowman's capsule or the glomerular capsule. I'm going to draw the whole thing for you, so that, and then we'll go ahead and label stuff. Look at me draw on the whole thing. And then we're going to go ahead and label stuff, right? Because that's what I just said I was going to do. Look, draw it exactly like this. Ooh, that's going to be a tight little turn right there. I made it. Okay. And then it dumps into this thing right here, which actually collects stuff from a whole bunch of nephrons. They all flow into this. Okay. Watch. This little cup, this little lobster claw is the glomerular capsule, glomerular capsule. And the glomerular capsule looks like a lobster claw. Womp, womp, womp. But it's actually a cross section of a cup. I can do that seriously like that. And there's blood vessels inside there. I'm going to talk about the blood supply to the nephron in a second because it's important. But don't forget that this is just a cross section. It actually is a little cup that we could stick our hand inside. It's a little cup, but it's a hollow cup. When you cross this single layer of cells right here, you're going to be inside a lumen. And the lumen is where we're going to collect. It's called filtrate. It's basically pre-P. It's the fluid that we filter out of the blood in order to make our urine. Once the filtrate is in the glomerular capsule or Bowman's capsule, it's going to flow into a structure called the proximal convoluted tubule. Proximal convoluted tubule. When I draw on nephrons, I draw my proximal convoluted tubule with little wiggly squigglies to remind me that it's super convoluted. It's like a knot of tubing. And that way I remember. This is my descending loop of Henley. So filtrate is going to come in through glomerular capsule into the proximal convoluted tubule and down the descending loop of Henley. This is, they call it a hairpin turn. It's a really, they can't be super long and they descend into the medulla of the kidney. And then guess what this one's called? This is the ascending loop of Henley. The ascending loop of Henley flows into the distal convoluted tubule. The distal convoluted tubule looks really long, but that's just so I could spread out my final structure, which is the collecting duct. And I think it's important to recognize the fact that many nephrons can feed into a single collecting duct. And then keep in mind that this is, in this lumen, this is where we're going to collect filtrate or pre-P. And then ultimately we're going to dump our pre-P into the collecting duct. Collecting duct ultimately ends up heading to the ureter and the bladder, just for perspective of where all this stuff ends up. The bladder is where your urine is. The ureter is the tube that connects your kidney to your bladder. And I think that that is extremely straightforward, right? I drew my distal convoluted tubule over here on purpose. There is an anatomical explanation for that. Now let's do the blood supply. How do we get blood into this scene so that we can filter it?