The archinephros, or holonephros, is a primitive kidney that has been retained by the larvae of hagfish and some caecilians.[1] A recent author has referred to this structure as "the hypothetical primitive kidney of ancestral vertebrates".[2] In the earliest vertebrates, this structure potentially extended the entire length of the body and consisted of paired segmental structures which drained via a pair of archinephrenic ducts into the cloaca.[1] The entire structure arises from the nephric ridge,[1] which in higher animal embryos gives rise to nephrotomes and the pronephroi at around 4 weeks gestation in humans.[3] The pronephroi are supplanted by mesonephroi and finally by definitive kidneys, the metanephroi, by around 5 weeks gestation.[3] The archinephros is nonfunctional in humans and other mammals.[4]

The three types of mature vertebrate kidneys develop from the archinephros: the pronephros from the front section, the mesonephros from the mid-section and the metanephros from the rear section.[5]

References

  1. ^ a b c Kisla, Seth M. (2011). Vertebrates: Structures and Functions. Boca Raton, Florida: Taylor & Francis (CRC Press). p. 434. ISBN 978-1-4398-4052-8 – via Google Books.
  2. ^ Shukla AK, Mani, NS (2021). "Comparative Anatomy: Urinogenital system of Vertebrates". In Tripathi RB, Vijaya P, Senan VP, Sona A (eds.). Recent Advancements and Research in Biological Sciences. Tamil Nadu, India: Thanuj International Publishers. p. 70. ISBN 978-81-952529-1-6 – via Google Books.
  3. ^ a b Larsen, William J. (1993). Human Embryology. Churchill Livingstone. pp. 235–6. ISBN 0-443-08724-5.
  4. ^ "Archinephros". WordInfo. Retrieved 23 September 2018.
  5. ^ "Archinephros". ENCYCLOPÆDIA BRITANNICA. Retrieved 23 September 2018.


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