pronephros उदाहरण वाक्य

Kidney development, also called " nephrogenesis ", proceeds through a series of three successive developmental phases : the pronephros, mesonephros, and metanephros.
These embryonic structures are on either side; the pronephros, the mesonephros and the metanephros of the kidney, and the Wolffian and M�llerian ducts of the sex organ.
I guess it's safe to assume that at the larval stage it's a pronephros, but does it change to a mesonephros at a later stage?
As this primordia begins to undergo epithelialization the anterior portions of the pronephros form rounded protrusions, which then later become the dorsal branches of the pronephros that link to nephrostomes ( distinct from nephrotomes ).
As this primordia begins to undergo epithelialization the anterior portions of the pronephros form rounded protrusions, which then later become the dorsal branches of the pronephros that link to nephrostomes ( distinct from nephrotomes ).

To me the most recognizable feature of true segments or somites in animals is that each one has a single unit of excretory tissue-see nephridium and nephrostome, though in vertebrates the pronephros regresses.
The pronephros disappears very early; the structural elements of the mesonephros mostly degenerate, but the gonad is developed in their place, with which the Wolffian duct remains as the duct in males, and the M�llerian as that of the female.
Wikipedia says that pronephros is an active organ in the adult hagfish and my book ( Introduction to Chordatezoology by J . M . J�rgensen ) says that in'some'hagfish the pronephros will turn into a bloodcreating organ,'like'mammalian bone marrow, thus making it an active organ but not the active kidney?
Wikipedia says that pronephros is an active organ in the adult hagfish and my book ( Introduction to Chordatezoology by J . M . J�rgensen ) says that in'some'hagfish the pronephros will turn into a bloodcreating organ,'like'mammalian bone marrow, thus making it an active organ but not the active kidney?