1. Control systems Objectives: What is a feedback diagram and how do I draw one? What is negative feedback? What are antagonistic effectors?

2. Keeping conditions inside your body the same is called homeostasis. All control systems have: –a receptor – which detects the stimuli (the change) –a processing centre – which receives the information –an effector – which produces an automatic response Control systems rely on feedback to maintain a steady state. Feedback is when the output of the system is fed back into the system as part of the input. –Negative feedback is when a change in the output of the system results in the system acting to reverse the change.

3. We can represent a control system in a feedback diagram: Detects increase Receives and processes information Detects increase Receives and processes information

4. Typically in a control system either one effector will do both jobs or two effectors that do opposite jobs. Effectors that have opposite effects are know as antagonistic effectors.