hey everyone it's s Earth register nurse rn.com and in this video I'm going to be going over kidney and nefron Anatomy this video will start our inlex review series over the renal system and at the end of this video don't forget to access the free quiz so let's get started first let's start out talking about the kidneys okay you have two kidneys you have a right kidney and a left kidney and your right kidney sets a little bit lower than the left kidney and the reason for this is because above the right kidney is the liver and to help accommodate the size of the liver that kidney has to be just a little bit down when you compare it to the left one now what do our kidneys do they are very very important in our survival just like with the heart we've learned that the heart will take our blood and pump that fresh oxygenated blood that it received through the lungs throughout the body well the kidneys receive that fresh blood through the renal artery and it will take that blood and it will filter that and after it filters it takes what it needs it will send it back through the renal vein so inside the kidneys you have filtration absorption and secretion and excretion going on and what will happen is that the kidneys will produce filtrate which is a liquid that will turn into urine it will go down through your urur you have one you have two that connect to each kidney then it will go down into the bladder to be stored and as the bladder becomes full you will feel the urged void and then it will exit through the urethra now let's look at the inside of the kidney if you took a kidney which um look is like a little bean shape if you've ever seen kidney beans they look like that but they're a lot bigger and you took it and you just cut it in half this is what it would look like on the inside so let's cover the basic anatomy of the kidney okay around the kidney is this outer capsule and it's called the renal capsule and this capsule what it does is that it gives the kidney its shape but it also helps protect the kidney from any infection that may be present in other organs because we don't want our kidneys to become infected if they become infected we can die now now inside the kidney this is what we are interested in because this is where things get done this is where our urine is going to be created so you have this outer part of this layer this is called the renal cortex then you have this little inner layer and this is called the renal medulla and please note where these layers are because it's going to be really important when we're talking about the nefron CU certain parts of the nefron are in the cortex versus the medulla and it'll all makees sense in the next video when we talk about the nefron physiology okay so we have that structure then inside where the medulla is we have these areas and I think they look like little seashells they're called renal pyramids and they have these striped areas why do they have these striped areas well inside the renal pyramid you have part of the nefron and the nefron is running straight parallel in these pyramids and it gives us this striped look to it then if you took away your renal artery and your renal vein and you looked behind it we would have this area right here and this is where the urine is really draining down through the uror into the bladder this is where once it's created in this area up in here it will drain down through these areas so let's go over these areas again you have your renal pyramids you have your renal papilla which um is the tip of the point of the pyramid then when your urine comes down through the renal pipila it will go into the kexes and you have the minor KX and you have the major KX then the urine will progress down through the renal pelvis which will go down into your urer then into the bladder and then the urethra now um in between your renal pyramids are renal columns and the renal columns contain a network of where your renal artery and your renal vein Branch off into these um capillaries and um arterials now let's look at the nefron okay if you're going to remember anything about the kidney the nefron is what you need to remember because this is the functional part of the kidney that um allows it to filter reabsorb and secrete um waste and things we don't need and turns into urine and each kidney contains millions of these little nephrons and they run in this area right here so let's dissect a nephron so here is a basic structure of a nephron and if you took a nefron and just stretched it out it would allow you to see these different Parts but in reality because you have millions of these just throughout here if you look at them they're all like twisted and they look convoluted and everything and they're all squeezed together and it would be really hard to tell what's what so um with nefron let's talk about this you have two I like to think of it as two different sections you have the section which is known as the renal cor pusle that is responsible for filtration and it is the Bowman's capsule and the glomus this is where filtration happens your blood's being filtered um things that are being pulled out or like water ions and waste and then you have the second section called the renal tubal and th it's this section and this is where reabsorption and secretion are happening what's happening is that you have this filtrate that's been created in by the renal cor pusle and you have these substances and water that's constantly flowing in and out of these tubules back into circulation which would be reabsorption or um it's moving out of circulation into the tubules which is called secretion so let's break this nefron down okay so going to the nefron remember um we just receive fresh blood from our hearts nice and oxygenated but it needs to be filtered so um urinal artery breaks off and it will break off into What's called the afron arterial and this is going to the first part of the Nephron the glomus afren means towards something so it hits the Glarus and the Glarus is this really unique structure if you ever look at a nefron look for the red part with all these squiggled up capillary looking areas and that's your glomus and so that's what it is is a bunch of capillaries just Twisted in this circular um shape and because of that the way it's formed um as that blood flows through there it creates this ultra filtration process which allows that blood as it's in a sense spinning through there to be filtered and to um release what's called filtrate down into this collection capsule called Bowman's capsule so you have this filtrate coming out of there and this filtrate will include like water um your electrolytes like pottassium chloride sodium magnesium calcium phosphate and waste like Ura and creatinin and it collects in there and it's called filtrate then um your glarius will go after the blood has filtered through there and it'll Branch off into What's called the ephant arterial ephant means away so it's leaving the Glarus and then the E arterial ghost just doesn't stop it still has a very important job to do it goes down and starts forming and twisting around those tubies and hanging out around there because it has a very important job as well the what it forms is called peritubal capillaries and um these are up here on these ducks and then when they go down and they form down where the loop of Henley is it's called the vastera which is a type of paru or capillary now what do these capillaries do okay so we have this filtrate going down through these tubules and remember what I said the renal tubules are responsible mainly for reabsorption and secretion so um in order for things to be reabsorbed and secreted so you can get rid of it you need something to help with that process so that's where those peritubal capillaries come into play so let's talk about these two terms cuz um in order to understand the physiology of the nefron which we're going to talk about in the next video in step you have to really understand these two terms reabsorption and secretion so reabsorption okay number one we call it reabsorption why not absorption well because we've already absorbed these substances that's how they've gotten our blood because remember it's went through the hearts came here been filtered and we got it where did we already absorb most of this nutrients out when we ate food through our GI tract because we eat your small intestine does most of the absorption so those specialized cells in there took the glucose the amino acids the potassium the calcium the sodium and took it and transported it where it needed to go and put it in the bloodstream and the heart now pumps it out and says kidneys do your job you filter this out choose what the body needs because the body likes homeostasis it likes a balance of water balance of electrolytes and a nice balance of waste specifically Ura and creatinin so as this filtrate has all of this nutrients in it it needs to be reabsorbed so that's what's going to happen it's going to flow through here and based on where it's at in these tubules because certain tubules absorb more here and more there it will be reabsorbed because we've already absorbed it once so it'll be reabsorbed and will flow through those peritubal capillaries which will eventually go to the renal vein which will eventually go back to the heart it'll get reoxygenated and the Beautiful Cy will just keep going and going now let's talk about secretion okay secretion the parital capillary is helping that because um these capillaries will carry like any um waste like Ura creatinin um or any drugs you've taken like antibiotics diuretics and will secrete their substances into the filate um and it will be taken and transported out and excreted as urine so that's how those two go hand inand okay now back to the nefron okay so all that filtrate is there in Bowman's capsule it's ready to go down in through these tubules to be reabsorbed or secreted so filtrate goes down the first part it hits is called the proximal convoluted tual and um this area is where a lot where actually most of your reabsorption is going to occur like um pretty much all of your glucose your amino acids um a lot of sodium and chloride and things like that things that are essential that your body really needs right away then the filtrate is going to travel down into the loop of Henley and this is really one of the most important parts and interesting parts of the nefron and remember what I said about these cortexes and the medulla the loop of Henley has a descending limb and an as ascending limb and they really each do their own different things and they're located the loop of Henley is mainly located in your renal medulla and the renal medulla is a very very salty area it's um hypertonic the interstial fluid that is in the renal medulla is hypertonic and this is very important animportant because this area is where most of your water absorption is going to occur and this is where your urine's really going to get concentrated then it's going the filtrat is going to go up through the distal convoluted tubal where some more absorption a little bit of secretion is going to occur then it's going to go down through your collecting ducts where everything's just going to be brushed up the last part of secretion and reabsorption is going to occur then it's ready to exit the body it's going to go down through the renal Pila which eventually will go into your KX your minor and major KX through your renal pelvis down through your Ur into the bladder and into the urethra so that is how urine is made through your nefron now don't forget to check out the next video about nefron physiology thank you so much for watch watching don't forget to take the free quiz and to subscribe to our channel for more videos