What you have to realize is that it's very, very rare to encounter positive feedback; there are very few mechanisms that act via positive feedback. Maintaining homeostasis requires negative feedback in order to keep levels of hormones, etc. within a narrow, physiologic range.
What you have to realize is that it's very, very rare to encounter positive feedback; there are very few mechanisms that act via positive feedback. Maintaining homeostasis requires negative feedback in order to keep levels of hormones, etc. within a narrow, physiologic range.
....And positive feedback is mainly used for devoting a disproportionally large amount of resources towards a small task, and is done only sporadically at best (like estrogen's effect on LH during ovulation).