1.1 A concept that refers to the physiological feedback mechanism from a sensor in response to a decrease in a set point and which aims to compensate the decrease in set point (e.g. a release of more Follicle stimulating hormone from the adenohypophysis to cause ovulation).

1.1.1 The description refers to a physiological feedback mechanism that responds to a change (decrease in a set point) by releasing more of a hormone (FSH) to cause an event (ovulation). This amplification of the initial stimulus, pushing the system towards a specific outcome rather than returning it to a baseline, is characteristic of a positive feedback mechanism. The LH/FSH surge leading to ovulation, triggered by rising estrogen, is a classic example of positive feedback. B) Positive feedback mechanism 1.1.2 The description refers to a physiological feedback mechanism that responds to a "saturation beyond a set point" and aims to "maintain the set point" by inhibiting a hormone. The example given, inhibition of Follicle stimulating hormone (FSH) by rising estrogen during the follicular phase, is a clear example where the product (estrogen) inhibits the release of the stimulating hormone (FSH) to prevent overstimulation and maintain balance. This counteraction of a change to return to a set point is characteristic of a negative feedback mechanism. C) Negative feedback mechanism