EXCRETORY SYSTEM

What is it? Purpose for excretory system… Filter blood and waste disposal Maintain blood osmolarity (water balance) Maintain blood pH Rid body system of ammonia NH4+ Metabolism of proteins and nucleic acids produce ammonia which is toxic

Structures involved

Water regulation and nitrogenous wastes (ammonia, urea, uric acid –all nitrogenous wastes) Every animal must have a system to regulate water because…homeostasis is vital and osmolarity must be regulated at a cellular level to ensure all above levels are regulated.

How have animals adapted to maintain water concentrations in the body but still get rid of nitrogenous waste? Freshwater fish: Marine fish: Amphibians: Birds: Reptiles: Mammals:

Focus on the kidney

Nephron Functions

Nephron Structure

Nephron Blood Supply

Urine formation

Permeable to water but not salt or solutes Permeable to salt but not water Permeable to water but not salt or solutes Active Transport

http://people.eku.edu/ritchisong/lec12.htm

URINARY SYSTEM – ADAM Modules. Glomerular filtration URINARY SYSTEM – ADAM Modules * Glomerular filtration * Early and late filtrate processing

Control - 694-695 ADH Aldosterone ANH Your turn! Add this to your notes in place of page 21