This lesson is an introduction to homeostasis and feedback loops. I have designed this lesson as a transition between GCSE and A level content. Students define the terms homeostasis and negative feedback. I have then used the examples of water and glucose regulation to allow students to work through the process. I have included a copy of the BBC short circuit video about Leah Betts as this highlights the issues associated with ecstacy and the failure of water regulation in the body. Next lesson we will focus on the control of heart and breathing rate and link this to exercise.