Organisms regulate complex systems through chemical interactions through feedback mechanisms. The feedback mechanism can respond to perturbation either as positive feedback (the same direction) or a negative feedback (opposite direction). The contractions in childbirth is an example of positive feedback. The hormone oxytocin is released in the body when contraction begins to further aid the contractions. An example of negative feedback is the regulation of blood glucose level. The continuous rise of blood glucose level may lead to diabetes.