Hi there. Today, we're going to discuss negative feedback loops, so negative feedback loops are critical in maintaining home yo Stasis in a lot of animals, including humans. So the goal of negative feedback loops is essentially to get back. Teoh what's called a set point, and that is, ah, pretty limited range of conditions that need to be maintained in order for the organism to stay alive. So, for example, humans have a set point of body temperature, a specific range of temperature that they need to stay within. Otherwise, you can, um, get too cold and get hypothermia. Or if you could get too hot, you can overheat. So the set point is really critical for, um, us to stay alive. So for negative feedback loops, um, the way, the way that you get back to this, that point is essentially to change the direction of the stimulus. So if we have our set point here and the stimulus raises whatever metric that is, then usually the body response will be to bring it back down. Conversely, if the stimulus lowers that our responses to bring it back up. So let's take a look at some examples of this. So if someone's hungry, for example, that means that they have gone below the set point of blood glucose levels in their blood. Um so the stimulus in which they need to eat goes down, and our response is we want to bring it back up, so that initiates certain signals within the body to get us to eat. So say we're eating and eating, and then blood glucose levels in our body rise, and that stimulus than our response is to bring it back down to normal glucose levels. And so ah, well will happen, then, is that insulin will be released from the pancreas and that causes cells to absorb glucose and stored as glycogen so that there's not as much glucose roaming around in our blood. And similarly, if you're eating a lot, then there are different responses throughout the body that will act. It's negative feedback signals to stop us from eating. So if this were a positive feedback loop, contraire Allee, then if we were hungry, we would just keep eating and eating and eating and never stop. Another example of this is the production of red blood cells. Um so specific hormone stimulates stimulates us to produce new red blood cells and bone marrow. But if there are plenty of red blood cells floating about, then the hormone is inhibited and won't be released by the kidney anymore. So that's another example. Have a negative feedback loop and often times with negative feedback loops You might have, um ah, threshold set point here. And what will happen is that it might go up and then I might go back down. But you're always trying to reach this middle point again, so it won't exactly be able to hit it right on the mark. The first time at a Josip basically tries to get as close to that set point as possible. So really, a negative feedback loop will, um, might kind of bungee around here. Um, it's not. It's not like a oneto one change, but it will always try to get back to this set point threshold that we need to stay alive.