Principles of homeostasis

• Homeostasis is the maintaining of a constant internal environment within restricted limits involving physiological control systems
• Negative feedback systems are used to maintain a balanced equilibrium
• Possession of separate mechanisms involving different directions give species a greater degree of control
• Positive feedback = when a deviation from an optimum causes changes that result in an even greater deviation
• Ectotherms gain most of their heat from the environment ➡️ they are dependent on external sources of heat
• Endotherms derive heat from metabolic processes
• Ectotherms have a narrower range of tolerance and narrower geographical range
• Endotherms have a greater range of tolerance and wider geographical range