 Well in this lecture we will be discussing that is vertebrate kidney or Vokonse kidney that is the metanephros which is the ultimate form of the kidney development which occurs as in The reptiles advanced reptiles the birds and the mammals So metanephros is a member of the final and most that is cordal pair That is the tail of the kidney because in the beginning that is a pro nephros It is the interior of the animal that is the first half of the kidney development But as the progress occurs the metanephros is quite behind the cordal region Development begins in the cordal region So the member of the final and most cordal pair of the vertebrate kidney This is the kidney that functions as a permanent adult kidney in reptiles birds and mammals So that is not present in the lower forms or the lower vertebrates And in this diagram we see that this is the metanephros This is the metanephric kidney which is a brown in color On both sides there are present the testes And the duct that is coming out of it is the urethra Which combines with that forms that is the main tube which comes from the kidney And then enters into the that is moves to the exterior through the urethra Now the physiological differences between these kidney types are primarily That related to the number of blood filtering unit So pro nephros may blood filtering unit they are very few Methanephros may ocesiada or metanephros may subcesiada That may go up to the million So the pro nephros is formed in the interior portion of the body cavity And contains fewer blood filtering units than either the metanephros or the metanephros That means that glomerulus or renal capsules That is very renal glomerulus or we call them bowman's capsules They are very few in number They are very few in number But as the progress has been evolutionarily or developmentally So this has increased and efficiency has increased The larger number of filtering units In the in the later that is in the metanephros Has allowed vertebrates to face the rigorous osmoregulatory and excretory demands Of the freshwater and terrestrial environment So in this you understand that freshwater animals or marine animals Adjusting in that environment is the work of the kidneys That is osmoregulation Then the regulation of solute So that the intestines can be maintained Now what follows is a presentation of how a few vertebrates That is they maintain their blood and solute concentration In different habitats in the seas and freshwater And as we move forward That is in our next chapters or next modules We will concentrate on this That how this water is maintained by fresh water fishes Or the marine water fishes So in this diagram, whatever we have read It has been presented in a very summarized form So this is a pronaphros This is the pronaphros This is this part of it is the pronaphros This is a pronaphric duct And this is all C-loam And this is glomerulus Which is a very early form of the kidney Then after that this is mesonaphros Which is in the amphibians So pronaphros it disappears It degenerates And this is a new part Which is the mesonaphros Has developed and along with it Glomeruli also has increased And after that this is metanaphros Which we are familiar with From this kidney And this is usually in big animals Reptile birds and mammals So in this there is a Beans shaped structure And this is mesonaphros Nephric portion That is degenerating With the passage of time So this is all about That is the vertebrate kidney variations Or in variations We have talked about three types That is pro, miso and metanaphros And in detail So this is all about this topic