BIOL 1002 Study Guide - Final Guide: Nephridium, Flame Cell, Renal Vein
Document Summary
Homeostasis - tendency of life to try and maintain the structure and regulate the internal environment. One of the biggest and most frequent homeostatic challenges an animal faces comes from the digestive process. The digestive system is unselective in what crosses the intestinal wall and enters the cells. Because of this unselective absorption animals are often presented with qualitative and quantitative differences of materials entering the bloodstream. The excretory system restores and maintains the proper internal regulation of these materials in the body despite differences in diet. The flame cells in flatworms are the simplest excretory system (see fig 35-1a). The tubes end at hollow bulbs called flame cells. Water and dissolved wastes are filtered into the bulbs. The cilia of the flame cell direct the fluid through tubes where water and nutrients are absorbed from the solution and more wastes are added from body cells.
