ZOO 2090 Lecture Notes - Lecture 17: Mesonephric Duct, Renal Corpuscle, Pronephros

• School: University of Guelph
• Department: Zoology
• Course: ZOO 2090
• Professor: Jinzhong Fu

Document Summary

Excretory system: remove wastes, in particular the nitrogenous wastes, and other harmful substances control osmosis - water and salt balance. Organs involved: kidney, gills, skin, part of the digestive system, salt glands reproductive system: Produce gametes, bring them together, provide nourishment, release the eggs and young. Organs involved: gonads, ducts, cloaca, copulatory organs kidney. Developmental origin of the elements of the excretory system. Pronephros segmented, usually the first 4 segments. Appear in all vertebrates (rudimentary form), and degenerated quickly functional in fish larvae and adults of hagfish and some teleosts in other fis, pronephros degenerates into head kidney", an organ limited to hemopoietic, lymphoid, and endocrine functions. Opisthonephros/mesonephros reduced segmentation in late larval and adults anamniotes, all or most of the mesomere posterior to pronephros forms one kidney, it is called opisthonephros. Among amniotes, the middle part of nephrogenic cord develop first, is called mesonephros and only present in fetuses, then degenerate.