This document discusses several components of animal excretory systems: 1. The excretory system regulates chemical composition of body fluids by removing waste and maintaining proper water, salt, and nutrient levels. 2. Osmoregulation controls water balance in aquatic, terrestrial, and hyperosmotic environments using different processes depending on the animal. Aquatic animals regulate to match surrounding water, while terrestrial animals conserve water through impermeable surfaces and kidneys. 3. Kidneys filter blood, reabsorb useful molecules, and excrete waste as urine, regulating water, waste, and pH balance.

1. Excretory System This system regulates the chemical composition of body fluids by removing metabolic wastes and retaining the proper amounts of water, salts, and nutrients.

2. FUNCTIONS: Collects water and filters body fluids Removes and concentrates waste products from body fluids and return other substances to body fluids as necessary for homeostasis Eliminates excretory products from the body

3. OSMOREGULATION in Animals a system of adaptations to control the water balance in organisms living in hyperosmotic, hypoosmotic or terrestrial environments. involves different processes depending on the animal due to the different environments they all live in. deals with osmosis of water between the internal environments of animals, with the outside environment

4. OSMOREGULATION in Animals AQUATIC "osmoconformers" don't actively regulate the osmolarity of their body fluids (but they may regulate the concentration of specific ions) body fluids ISOSMOTIC to the surrounding seawater

5. OSMOREGULATION in Animals TERRESTRIAL "osmoregulators" Most terrestrial animals are covered with a relatively impervious surface that helps prevent dehydration ( skin , exoskeleton ). Some animals are nocturnal, while most others have adapted KIDNEYS that can conserve water in some fashion.

6. NEPHRIC Organs Kidneys are involved in water balance, waste excretion and ph balance. Blood is filtered through pores into the Bowman's capsule from the first capillary bed. In the renal tubules, certain molecules (amino acids, glucose etc.) get reabsorbed into the second capillary bed, while other molecules are secreted into the tubule. Most of the water and salt is reabsorbed from these tubules; the remainder is excreted as URINE .

7. GREEN GLANDS These are paired glands found in the anterior of many CRUSTACEANS that have excretory functions. The glands consist of three basic parts: end sac convoluted tubules exit duct

8. Malphigian Tubules These organs are evaginations of the gut which serve as excretory organs in such TERRESTRIAL ANTHROPODS as insects, centipedes, millipedes and arachnids These blind pouches are bathed in blood in the sinuses of the open circulatory system . Wastes enter the tubules and are removed via the hindgut . nitrogenous wastes are removed in the form of uric acid