1 00:00:00,026 --> 00:00:07,709 I'm gonna draw for you two of the most important organs in the body. 2 00:00:07,709 --> 00:00:13,871 They're on the left and right side of the body and look pretty much like that. 3 00:00:13,871 --> 00:00:18,058 They look like kidney beans and that's what they are, they're kidneys. 4 00:00:18,058 --> 00:00:25,176 So we have some arteries, the renal arteries, that flow into them. 5 00:00:25,176 --> 00:00:30,835 And renal is just a word referring to kidneys. 6 00:00:30,835 --> 00:00:37,277 And we've got renal veins with blood flowing back out of them. 7 00:00:37,277 --> 00:00:43,437 Once the blood is headed back to the heart, we call it renal vein. 8 00:00:43,437 --> 00:00:46,343 And there are two of them. 9 00:00:46,343 --> 00:00:50,674 The most important part of these kidneys, certainly the part that makes them unique, 10 00:00:50,674 --> 00:00:53,938 is that they have these ureters. 11 00:00:53,938 --> 00:00:59,800 And these ureters drain urine into a bladder. 12 00:00:59,800 --> 00:01:04,100 I'm gonna draw that right here, that's the bladder. 13 00:01:04,100 --> 00:01:10,176 The ureters are the third tube coming out of our kidney. 14 00:01:10,176 --> 00:01:17,404 When you're ready to urinate you can release all that urine from your bladder into the outside world. 15 00:01:17,404 --> 00:01:21,773 There's three basic things that I want you to remember coming into or out of kidneys. 16 00:01:21,773 --> 00:01:25,600 The renal arteries, the renal veins and the ureters. 17 00:01:25,600 --> 00:01:29,000 To really make sense of it, you gotta think about how the artery might split up. 18 00:01:29,000 --> 00:01:32,105 So we go back to the artery and we follow it. 19 00:01:32,105 --> 00:01:38,873 It starts kind of branching into five little branches, it might have more branches out of those branches, 20 00:01:38,873 --> 00:01:44,725 and finally maybe even some more branches, eventually it's not even an artery anymore, right? 21 00:01:44,725 --> 00:01:50,520 All these little branches are so tiny, you would call them arterioles. 22 00:01:50,520 --> 00:01:54,896 Let's just take this arteriole, this little guy and let's see what happens. 23 00:01:54,896 --> 00:02:02,293 So let's take that little guy and show you on the left side of the screen what he looks like. 24 00:02:02,293 --> 00:02:05,462 Let's look at this arteriole a little bit closer. 25 00:02:05,462 --> 00:02:10,836 This is our Afferent arteriole. 26 00:02:10,836 --> 00:02:17,944 It's called afferent because it's headed towards something. Afferent arteriole. 27 00:02:17,944 --> 00:02:21,957 Don't forget where it comes from, it's coming from the renal artery. 28 00:02:21,957 --> 00:02:29,332 The blood is coming from the renal artery and it's headed towards something and that's this. 29 00:02:29,332 --> 00:02:38,635 The artery or the arteriole rather starts making a lot of little turnbacks on itself and finally straightens out. 30 00:02:38,635 --> 00:02:42,352 When it does it's called the Efferent arteriole. 31 00:02:42,352 --> 00:02:52,861 That's how we keep straight whether it's coming or going from this little network of blood vessels. 32 00:02:52,861 --> 00:03:02,938 This little network of blood vessels, if you look under a microscope, is actually being hugged by something like this. 33 00:03:02,938 --> 00:03:07,443 This is the first time we're taking a look at something that isn't a blood vessel in the kidney, 34 00:03:07,443 --> 00:03:10,859 it begins our journey of urine. 35 00:03:10,859 --> 00:03:21,632 This thing is called the Bowman's capsule, this is the thing in yellow I've drawn for you. 36 00:03:21,632 --> 00:03:25,865 Whenever things are named like this, you have to wonder 'Who was mister Bowman?' 37 00:03:25,865 --> 00:03:34,062 Mister Bowman, turns out, was from England, actually he was a very curious fellow. 38 00:03:34,062 --> 00:03:43,465 So he looked under a microscope and he noticed that, if you look right where the little cups of blood vessels are, 39 00:03:43,465 --> 00:03:51,162 you can actually see that there's something surrounding them, each of them. So he called that Bowman's capsule. 40 00:03:51,162 --> 00:03:54,403 And that's what we still call it today. 41 00:03:54,403 --> 00:04:00,960 England was laying claim on parts of the kidney anatomy, we might not even have known then. 42 00:04:00,960 --> 00:04:03,522 So that's Bowman's capsule. 43 00:04:03,522 --> 00:04:09,670 That's the first part of the nephron. I'll actually show you all the parts of the nephron. 44 00:04:09,670 --> 00:04:17,859 The next part of the nephron, nephron just means kind of the unit of the kidney we care about. 45 00:04:17,859 --> 00:04:22,193 The next part is looking really squiggly, very convoluted, right? 46 00:04:22,193 --> 00:04:29,061 I'm trying to draw it that way purposefully, because I want you to remember it's called the proximal, 47 00:04:29,061 --> 00:04:39,359 because it's near the Bowman's capsule, thus proximal, convoluted tubule. 48 00:04:39,359 --> 00:04:43,523 Because this is one long tubule, like a little tube. 49 00:04:43,523 --> 00:04:55,097 This is the proximal convoluted tubule, the part of the nephron after Bowman's capsule is the proximal convoluted tubule. 50 00:04:55,097 --> 00:05:01,661 Then it gets into a long deep loop, long loop like that that. 51 00:05:01,661 --> 00:05:10,069 This loop is called the loop of Henle. 52 00:05:10,069 --> 00:05:15,328 You're seeing now part three is called the loop of Henle. 53 00:05:15,328 --> 00:05:17,427 Loop makes sense, but 'of Henle'? 54 00:05:17,427 --> 00:05:22,194 You've got to wonder again 'Is this another British guy, who's mister Henle?' 55 00:05:22,194 --> 00:05:27,769 Mister Henle, turns out, is actually not British, he's from another part of Europe, 56 00:05:27,769 --> 00:05:30,758 maybe you can guess before I finish this drawing. 57 00:05:30,758 --> 00:05:38,005 He discovered that if you follow the nephron deep into the middle of the kidney, 58 00:05:38,005 --> 00:05:43,791 it has this little loops, very delicate loops, but very important in helping urine form. 59 00:05:43,791 --> 00:05:53,165 He was a German scientist. If the British are going to identify something, so will the Germans. 60 00:05:53,165 --> 00:05:54,893 We still call that the loop of Henle. 61 00:05:54,893 --> 00:06:04,025 After the loop of Henle we have another area that is very convoluted. 62 00:06:04,025 --> 00:06:05,859 You can guess how we'll call this. 63 00:06:05,859 --> 00:06:09,669 When we call things, we try to stay consistent, 64 00:06:09,669 --> 00:06:13,126 If the first part was called the proximal convoluted tubule, 65 00:06:13,126 --> 00:06:19,126 we would call this not the proximal, because it's not near anymore, but a little further away, 66 00:06:19,126 --> 00:06:28,072 we call this the distal, meaning further away, convoluted, 'cause it's still convoluted, tubule. 67 00:06:28,072 --> 00:06:30,597 This is the distal convoluted tubule. 68 00:06:30,597 --> 00:06:40,294 Finally there's a fifth part of all this, the fifth part of this is a giant tube of collection. 69 00:06:40,294 --> 00:06:43,263 All this stuff goes to a collection tube. 70 00:06:43,263 --> 00:06:51,399 I'm actually showing you where all the other distal convoluted tubes might be dumping in as well. 71 00:06:51,476 --> 00:07:00,512 Eventually all this stuff is gonna go to the same place, which is down to the ureter. 72 00:07:00,512 --> 00:07:03,636 We've seen now how things go to the ureter. 73 00:07:03,636 --> 00:07:08,333 You can see how things come from the renal artery, but you're probably still wondering, 74 00:07:08,333 --> 00:07:15,779 (oh, I see I didn't label this for you, this is the collecting tube) 75 00:07:15,995 --> 00:07:21,755 You're probably still wondering 'Where is the renal vein in all this?' 76 00:07:21,755 --> 00:07:26,662 I still drew the efferent arteriole as being red, it has oxygen. 77 00:07:26,662 --> 00:07:30,857 Where does the venous blood come from? 78 00:07:30,857 --> 00:07:42,928 The answer is right here, so you basically get red blood, oxygenated blood, flowing over all these parts of the tubule. 79 00:07:42,928 --> 00:07:47,493 Oxygenated blood. 80 00:07:47,493 --> 00:07:58,189 The proximal convoluted tubule, the loop of Henle, the distal convoluted tubule, all get wonderful blood. 81 00:07:58,189 --> 00:08:07,121 Finally, when all that is set and done, it all drains into one thing, one final renal vein. 82 00:08:07,121 --> 00:08:11,659 And that's with all of the blood coming together. 83 00:08:11,659 --> 00:08:28,124 This little network of capillaries are considered the peritubular, going around the tubule, peritubular capillaries. 84 00:08:28,124 --> 00:08:29,823 That makes sense. 85 00:08:29,823 --> 00:08:35,825 You can see the renal artery blood coming in, going through the afferent arteriole, the efferent arteriole, 86 00:08:35,825 --> 00:08:41,623 draining back into the peritubular capillaries and finally the renal vein. 87 00:08:41,623 --> 00:08:48,663 This important structure in yellow that I've drawn, has five parts to it. 88 00:08:48,663 --> 00:08:55,291 All five parts together are called the nephron. 89 00:08:55,291 --> 00:09:02,228 This is an important structure and we'll talk about the different parts of the nephron in future videos. 90 00:09:02,228 --> 00:09:06,228 This is an important structure, at least you'll get a sense of what it looks like and what the different parts are called.