Excretory System (Urinary System) Thermo & Osmoregula:on Goals for the Day •  Be able to describe the differences between ectotherms & endotherms in regards to thermoregula+on •  Be able to describe the differences between saltwater & freshwater fish in terms of osmoregula+on. Ques:on of the Day •  Try to define thermoregula:on & osmoregula:on. Ques:on of the Day •  Thermoregula:on – regula:on of heat (in specific regard to body heat) •  Osmoregula:on – regula:on of water, in regards to the amount of water in our bodies propor:onal to salt and ion concentra:ons. Thermoregula:on •  Ectotherms – “coldblooded animals” – use environment to regula:on body temperature. •  Endotherms – “warm-­‐blooded animals” – maintain a stable internal environment through metabolic reac:ons. Advantages/Disadvantages of being Endothermic? Advantages Disadvantages Advantages/Disadvantages of being Ectothermic? Advantages Disadvantages Osmoregula:on •  What are 3 ways that water enters our bodies? –  Drinking –  Food –  Metabolism Osmoregula:on •  Fish •  Mammals/Amphibians •  Birds/Rep:les Osmoregula:on •  Review Diffusion/Osmosis Osmoregula:on in Fish •  Review Diffusion/Osmosis •  Freshwater Fish –  Passively gain water through gills –  _______tonic to surroundings –  Do not drink –  Must excrete large amounts of dilute (Watery) urine •  Saltwater (Marine) Fish –  Passively lose water through gills –  _______tonic to surroundings –  Must drink saltwater to gain water –  Ac:vely transport salts back through gills Body Fluid Regula:on in Bony Fishes 13 Nitrogen •  How do animals get nitrogen? •  What is it used for? Nitrogenous Wastes Nitrogenous Wastes 16 Goals for the Day •  Be able to describe the differences in excretory systems of different organisms, and the various waste products they produce Ques:on of the Day •  Explain the problems of osmosregula:on in freshwater & saltwater fish Nitrogenous Wastes: Ammonia Nitrogenous Wastes: Urea Nitrogenous Wastes: Uric Acid What structure in humans is responsible for dealing with nitrogenous waste removal? Nephron Nephron