ACB 406.3 Lecture Notes - Lecture 10: Agnatha, Pronephros, Kidney Development

• School: U of S
• Department: Anatomy and Cell Biology
• Course: ACB 406.3
• Professor: Helen Nichol

Document Summary

L10 excretory system: some vertebrates have other routes of excretion other than kidneys, lungs, gills, skin, kidneys. Functions of the kidney: excretion of nitrogenous wastes, maintenance of water balance, maintenance of ionic balance. Mechanisms: glomerular filtration, tubular reabsorption, secretion, hormonal control. Evolution of the kidney is recapitulated in the embryo: pronephros agnathans (jawless fish) e. g. larval lamprey, mesonephros fish and amphibians, metanephros reptiles, birds and mammals. *fluid that enters the coelom comes from 3 sources: Fluid from the gills, body surface and from blood at the glomus (primitive glomerulus not surrou(cid:374)ded (cid:271)(cid:455) bo(cid:449)(cid:373)a(cid:374)"s (cid:272)apsule) enters the coelom. This fluid is drawn into nephrostomes, a ciliate funnel. Fluid then goes to the pronephric tubules (salts and other valuable metabolites are reabsorbed in the tubules and the waste passes into. Picture: glomeruli coelom nephrostome pronephric tubules. *only primitive bony fish have nephrostomes (e. g. gars) Kidney of boney fish: pronephros becomes primary hemopoietic organ of the adult (cid:272)alled (cid:862)head kidney(cid:863)