1. Excretion: Disposal of Nitrogenous Wastes ammonia is too toxic to be stored land animals must dispose of Nitrogen in different form: Urea or Uric Acid Urea can be stored in conc’d. form but requires water for disposal Uric acid allows for water conservation

2. The Workhorse of the Excretory System: the Kidney Kidneys filter the blood, helping to regulate the amount of water and salts in the body ’ s fluids, and thus maintaining homeostasis.

3. The Nephron is the functional unit of the Kidney

4. Details of Nephron Structure

5. The key functions of the excretory system are: Filtration Reabsorption (from filtrate to blood) Secretion (from blood to filtrate) Excretion

6. Reabsorption & Secretion in a Nephron