endocrine system and more

Well done everyone for getting through the first half hour of today’s session! It’s going to be a heavy one today, so try and keep up! Throughout the lesson we’ll post a set or two of notes, summarising everything we’ve learnt so far. Keep a copy of these if you think they’ll be useful. Let’s go! /// Don’t forget to refresh yourselves of the objectives every so often to make sure you’re staying on track. /// Homeostasis: the maintenance of a constant internal environment. This is maintained by the endocrine and nervous systems. /// Why do we need homeostasis? For optimum conditions for enzyme action and cell function. Can you remember what factors need to be controlled in the human body? Why do they need to be monitored? /// We moved on to have a look at the components of a homeostatic system: stimulus (change in environment); receptor (detects change); control centre (regulates the change); effector (causes corrective change); response (returns homeostasis). /// Stimulus: physical, chemical or biological factor causing the body to move away from its normal. Receptor: sensory organs that detect the change in the body’s environment. Control centre: receptor sends information here  control centre sends information to effector, telling it to oppose the change and bring conditions back to the optimum. Effectors: glands and muscles that initiate movement or hormone secretion. Response: corrects the initial change that occurred due to the stimulus. /// Have a go at working out all of the components of a homeostasis system for temperature and blood glucose. /// Negative feedback: allows maintenance of a set point and prevents overshoot. Negative feedback counteracts a change – just like we’ve talked about before. The change is fixed, and then anymore change away from the baseline is stopped. Positive feedback is the opposite. It amplifies the change that is first initiated, making the change greater and greater away from the baseline. ///

One hour down! Woo! Well done everyone for keeping up, we’ll have a five-minute rest break shortly. /// THERMOREGULATION! When we detect cold temperatures, the hair on our body stands…