in this video we're going to look at the external anatomy of the kidney and a good place to start with that is with the vasculature as the kidneys develop multiple kidneys pop up along two tubes now many of these kidneys will regress and only the last two will persist attached to that tube so here is the abdominal aorta and we know that eventually the delay order is going to split into the common iliac arteries well off that abdominal aorta is the renal artery and the right renal artery artery is going to be longer than the left and the reason that it's longer than the left is that dominantly Horta is offset to the left side of the body so that left renal artery is going to be a bit shorter than the right you also might notice that I've drawn the right renal artery lower than the left and that's because the liver takes up a lot of that upper right quadrant of the abdominal pelvic cavity and this right kidney therefore it needs to sit a little bit lower now the left renal vein is going to be longer and the right renal vein is going to be shorter because the inferior vena cava is over here on the right side of the body and we're going to have those common iliac coming up behind the aorta draining into the inferior vena cava you have the important left go not only in as well I think if these is the two soccer players and the blue team has his arm across the chest of the red team because they're both going for a ball over here but the red team has his legs in front of the blue team so who's going to get that ball first okay we have the paired right and left kidneys okay and they feed into a tube called the ureter through the renal pelvis now an important anatomical relationship how you tell a right kidney from a left kidney needs to include that renal pelvis and the ureters that lead down to the urinary bladder and the urethra now the urethra and a male is much longer than in a female but these ureters are going to enter into the bladder from the posterior aspect and they enter in it's something called the tri go this is a specialized epithelium in this area that's a little bit different then the transitional epithelium of the rest of the bladder will open up into that that urethra drawn from the side we have this urinary bladder and the ureter comes down and then enters bilaterally into the back of the urinary bladder as the urinary bladder fills to prevent backflow and buildup in the kidneys the ureters going to become more and more bent this is a nice design because it occludes backflow up the order which would build pressure in the kidney and possibly cause hydronephrosis or water on the king ok back to the relationship the way that you tell a right kidney from a left kidney first you need to orient the kidney so that the concave surface the concave surface is facing medially the convex surface if we were facing a surface it would be like pulling the mirror with suction cups towards us that's convex this would be if we're facing it like pushing the mare in concave you face the concave surface immediately convex surface laterally you know that that ureter needs to drain downward so you face the renal pelvis this area that drains into the ureter inferiorly now the last step because this could easily just flip over like a page of a book and be this kidney how do we know which is which well the last step is to know that the blood vessels appear to enter anterior to the renal pelvis so see how these vessels are in front if I flip this over the vessels would appear behind that renal pelvis here we see the back of the there the renal pelvis but it's behind these blood vessels you might have cluttered this a bit too much it's behind these blood vessels so that's the orientation to get the kidneys in the correct position [Music] [Applause] [Music] now we've seen the components of the urinary system here we've seen those kidneys which are going to be the star of the show the ureters the urinary bladder and the urethra but we want to focus in more on the kidneys and so what I'm going to do is I'm going to draw a larger kidney here and I'm going to draw this kidney from a posterior view here's the ureter and here's that concave surface now if this is a posterior view I'm going to put the renal vein and the renal artery behind that renal pelvis now one of the things about the kidney is that it has a fibrous capsule superficial fashio and a paranal fat capsule that's going to help protect it so the renal fascia is an outer layer of dense fibrous connective tissue that anchors the kidney to surrounding structures so first we're going to have this dense fibrous connective tissue that anchors the kidney to surrounding structures and in position it also somewhat encapsulates the suprarenal gland the separate organ on topic indeed now deep to that we have adipose tissue or the para renal fat cap so this is going to have some adipose tissue both of these help provide support to the kidney and protect it from injury so that how to post adds a little bit of cushion in here a little bit of cushion thanks to that fat now in wasting diseases you can develop something called renal ptosis and it's spelled with a P renal ptosis it's kind of a clinical correlate and it's filled with a P P TOS is okay ptosis means drooping okay you can have ocular ptosis where the eyes kind of sag and drew them you can have renal ptosis where this Peregrino fat capsule actually that adipose starts to get metabolized for body energy in stores and this whole kidney sags and drops and that's a very dangerous condition because when it sags and drops it kinks the vein that sweeps blood away and pressure can build within the kidney fluid can accumulate within the kidney so this is common in wasting diseases you can think of HIV people who just had chemotherapy anorexia I've actually experienced this when I was in better shape and an athlete I got so lean that I started metabolizing the fat around the kidney and experienced hydronephrosis or water on the kidney it's really water pressure within the kidney but it can damage the important units the nephrons within the kidneys common in waist diseases and this can lead to to need to hydro Neff roses hydro Nefer OSIS I talked about another time that we see hydronephrosis and that's in obesity when the person intestines grow so much that not the celiac trunk but the superior mesenteric artery this elephant trunk of an artery that's going to feed the intestines pinches that arm that's coming across to drain the left kidney this artery actually comes up over that left renal vein and it can pinch that and one of the conditions we'll see is we'll see the testicular or ovair ovary on the left become inflamed and swollen we'll also see that kidney develop hydronephrosis or water they say on the kidney but it's really in the kidney it's this swelling of the kidney because the kidneys not draining well not through the venous blood or potentially not through the ureter and because that left go not all vein drains into the left renal vein to get across live you see it would never want to cut across the way that right testicular vein can because it would pass by this aorta and become compressed the way that this blood vessel has compressed this arm but that's only when the intestines are heavy and somebody's in a supine position or laying on their back too much and it can pinch this another time we see these blood vessels getting pinched is during pregnancy lying on her back the weight of the fetus can potentially compress some of these veins and now the blood flow needs to find alternative routes this is where a woman might experience hemorrhoids or the epigastric Pharisees known it known as kaput Medusa because it looks like kind of snakes are crawling up the belly with those distended veins or esophageal varices the veins leading up the saphenous to try to take an alternative route into the as igus vein that can drain into that superior vena cava to get back to the heart these alternative routes can form varices or bulges in the veins okay I don't want to get too off-topic hydronephrosis can be caused by infection of the kidney which would be nephritis which also accompanies infection of the renal pelvis so you'll hear Politis which is infection of the renal pelvis itis is inflammation or here you'll hear is pilo nephritis nephritis is infection of the kidney itself put them together because you're barely gonna have one without the other because the only way for this to get infected thanks to this fibrous capsule the paranal fat capsule and a renal fashio that helps isolate the kidney from all other retroperitoneal and by retroperitoneal I mean the kidneys not in the abdominal pelvic cavity it's actually faded out behind it behind a thin layer of peritoneum this helps separate it from all other structures so it's very difficult to infect the kidney from outside but crawling up the the urethra into the urinary bladder up the ureter into the renal pelvis bacteria can make their way and potentially infect the kidney itself if you're gonna have pi lightest you're likely gonna have nephritis and if you have enough fry this you've definitely got an infection in the renal pelvis so they've oftentimes just combine this into PI lo nephritis I hope I'm spelling some of these correctly gonna ask you to look them up in your book as well these are infection these are infections and inflammation that accompanies infections of the renal pelvis this is the renal pelvis and kidney okay to finish up the external anatomy I want to talk about one other protective structure here and that's the last two ribs ribs 11 and 12 so rib oh if this is a posterior view on the right the rib would be coming from the back kind of around this way but those last two ribs don't go the full distance they only come far enough to kind of cover the back side of this kidney so if I can imagine flipping this over they would be coming from let me see the left side kind of coming down around the back here this will be ribbed 12 let's do rib 11 okay not not perfect here one of the common injuries to the kidney because the bottom end of it isn't completely protected is damage to the Sereno artery whenever there's a blow to the back I always think of biking accidents or motor vehicle accidents or snowboarding in a halfpipe and falling backwards and hitting the edge of the halfpipe hitting the edge of that halfpipe on their back right here and that would rupture or damage either the kidney or that renal artery okay so these are some of the external features of the kidney I want to add one more and that's this entire region called the hilum the hilum of any organ is where the blood vessels and tubes feeding that organ kind of enter so it's more of a theoretical space than an actual structure and it includes where all these blood vessels are coming in okay I'm going to pick up with some of the additional internal anatomy in the next video