 In this practical, we will learn about the excretory system of vertebrates. The highest category of the animal kingdom and vertebrates contain the vertebral column. Major excretory organ that is present in the vertebrates is the kidneys. They play important role in the formation of excretory waste. Other than kidneys, different excretory glands are present in the vertebrates. For example, lungs, gills, liver, intestine and skin. They all play together along with the kidneys to remove the excretory waste from the body. We will learn in this practical about the excretory system of reptiles and excretory system of human. If we talk about reptiles, there are very small kidneys present in both sides of the vertebral column. And different excretory wastes are removed from the body in different reptiles. If we talk about lizards, snakes and crocodiles, excretory wastes are euric acid. Whereas marine iguanas have excretory wastes. Reptiles produce mostly dilute urine. Because the structure of their body is not so well developed that it can produce concentrated urine. Other than kidneys, different glands are present in the vertebrates. Like salt glands are present in the vertebrates and different locations are present in the vertebrates. If we talk about marine iguanas, most of the salt glands are present in the head region. Salt glands are present in the head region. And the water or salt is removed in the liquid form. It is removed from the head region with a flow. Next, if we talk about crocodiles, salt glands are present in the head region. Salt glands are present in both sides. And excretory wastes are present in the removal. Next, if we talk about lizards, there are kidneys present in both sides. The vertebral column is in the centre and the kidneys are present on both sides. Most of the types of kidneys are metanaphric kidneys. The highest-dwelled form of kidneys in the vertebrates are metanaphric kidneys. If we look at the structure of the kidneys and the reproductive organs, we can see that the lizards or reptiles are mostly reproductive organs. And the excretory organs are connected to each other. So, when these organs are connected to each other, we can also call the urogenital duct or the urogenital system. These tubules are shown here. These tubules are called metanaphros. These tubules are derived from naphrons. If you have blood from these metanaphros, the extra water or salt is absorbed in these tubules. These tubules are absorbed in the rectum. Now, for excretive waste removal, there is a single opening for excretory organs. The reproductive system is also connected to these tubules. The gametes will also go out through these tubules. The digestive system waste will also go out through these tubules. The excretory system waste, for example, uren, will also be removed out of this single opening. These tubules are ovaries. The ovaries have an opening, which is called oviduct, which passes the gametes through the clioca. This is its female structure. This is its male structure. The same is present in the male, which is called metanaphric kidney. And in the kidney, metanaphrons are present. The uren formation is done. The extra material is absorbed through the blood. And it is removed from the outer body through the clioca. The male gametes are also removed from the ducts. The clioca is removed from the outer body. This was the excretory system of reptiles. And we saw the excretory system of lizards. Next, we have the human excretory system. And the human excretory system depends on the different organs. The first organ is the kidneys, which are present on both the sides. And the next structure is the ureters. The uren is present in the ureters of the kidneys. After that, it goes into a storage muscular organ, which is called a bladder. And the bladder ends in the urethra. And the uren is removed from the outer body. In the excretory system of humans, for example, you have vertebrates, for example, amphibians, reptiles. And there is a difference in the bird sound. In this, there is a separate opening. For reproductive gametes, for excretive waste, there is a separate opening. And for digestive waste, there is a separate opening. If we look at the kidney structure, the outer part is called cortex. The inner part is called medulla. And these two parts are called pelvis. And there are many collecting ducts in the pelvis. And they lead to ureter. And ureter leads to bladder. If we look at the nephron structure, which is a single unit in the kidney, means that the kidney is formed from many nephrons. So, in the nephron structure, we first see a cup shape, which is called bowman capsule. And in the bowman capsule, there are many bundles of arteries, which are called glomerulus. The blood that is formed from the glomerulus, the small pores are formed from it. The air enters the bowman capsule. And in this, there are no red blood cells and no proteins. Because their size is large. So, they cannot pass on such small pores. So, the bowman capsule leads to proximal tibials. Some of the material is absorbed in the blood. Some are absorbed. And proximal convoluted tibials lead to a q-shaped structure, which is called loop-of-handle. We just talked about that this laser does not develop that much. So, there are two loops in the loop-of-handle. The one coming down is called descending loop-of-handle. The one going up is called ascending loop-of-handle. The descending loop-of-handle, which is water, is absorbed in the descending loop-of-handle. Whereas, the ascending loop-of-handle is completely impermeable for the absorption of water. No absorption of water can be done in the ascending loop-of-handle. The ascending loop-of-handle leads to a lot of convoluted tibials. These are called distal tibials. These distal tibials lead to the collecting duct. The collecting duct opens up in the renal pelvis and leads to the ureters. This is how urine formation and excretive waste are removed from the human body. In addition to kidneys, there are many other accessory excretive organs that play an important role in the removal of waste from the body. If we look here, the first organ is the skin. It is mostly removed from the skin by the skin. Sorts, especially sodium chloride, in the form of sweat with the help of sweat glands. Next, you have lungs. In the lungs, it is mostly removed through water and weathers. After that, you have the liver. All the metabolism of drugs in the liver removes the waste from the liver. It comes into the blood and goes into the kidneys and is removed from the body through urine. After that, there is a major organ in the kidneys and it plays a more or less role in water absorption and water removal. This was the excretive system of humans. What did we learn in this practical? Excretive organs, vertebrates. In this, we saw the excretive organ of reptiles and humans. Kidneys are present in reptiles, whereas the loop of the anus is not present. There is not much dwelled structure. Due to which reptiles cannot produce concentrated urine. Whereas we have humans, the loop of the anus is also dwelled. Kidneys are also dwelled. In addition, there is ureter and bladder. There is ureter for urine storage and there is a separate opening for urine removal. Excretive waste varies in reptiles. Some have uric acid and some have urea. Other than kidneys, many accessory glands are present. For example, gills are present in fishes. If we talk about humans, they have skin, lungs, kidneys and liver. What do they do? They work as excretive organs and remove the waste. In this way, animals remove excessive material from their body and help in their survival. Thank you very much. Good luck.