Draft

Feedback loops are something that occur in many different aspects of life. They are an observation found in all different scientififc studies. This year alone I've learned about them in terms of human physiology and in climatology. Feedback loops are kind of like cycles. There is a signal that starts a chain reaction that leads to a response. Sometimes the response inhibits the initial siglanl, a negative feedback, and sometimes the response leads to an increase in the signal. An example of a positive feedback loop is chidbirth. The contraction leads to a nerve impulse that signals the hypothalamus to release the hormone oxytocin. The release of oxytocin leads to more contractions. Which then lead to more production of the hormone. The initial contraction leads to a stimulus that in the end results in more contractions. Blood clotting is another example of positive feedback because when a vessel is damaged platelets start to cling to it and when they cling they release a hormone that attracts more platelets. So the initial blood clotting leads to more blood clotting. The initial stimulus leads to an increase in the final product. 

Negative feedback has the opposite result. Negative feedback most often keeps something more towards equilibrium whereas positive feedback escalates, so usually only occurs in special instances. An example of negative feedback is thermoregulation. If a body temperature increase, measures are taken in order to try and lower the body temperature. So the initial increase leads to a decrease in body temp, therefore a negative response. Another example is blood sugar levels. When glucose levels are high, insulin is released to decrease levels. When levels are low, gllucagon is released to increase levels. The initial stimulus results in something trying to lower the signal.