Homeostasis and Negative/Positive Feedback

Did you know, just sitting here right now, you’re doing something absolutely remarkable? Well you…your cells, tissues, organs, organ systems---yep we just leveled up those biological levels of organization--- they’re all working towards something called homeostasis. It’s a state of balance. Yes, homeostasis means many things in your body: for example, that your blood stays within

a certain pH level range. It means your blood glucose remains within a certain range. It means your internal body temperature stays within a certain range. See, we’ve mentioned the major body systems before, and that they work together---and today we’re going to talk about HOW they work together---using something called positive and negative feedback.

And, also, how this relates to homeostasis. So many years ago, I had a pet bearded dragon. Her name was Debbie and she was the best lizard ever. Debbie used to sit on our couch with me when I’d watch TV. And she loved to have her chin scratched. I even got her a bearded dragon leash so I could take her outside…yeah, they make those…anyway,

Debbie loved her heat lamp. She would sit under the heat lamp on her rock. And when she got too hot, she would get off her rock and out of the heat lamp range and go somewhere else. She had a huge enclosure too because, I wanted Debbie to be a happy lizard, so she could

find an ideal temperature. Well why all this talk about Debbie? Well, Debbie is an example of an animal that some people refer to as cold-blooded. Or a fancier term, ectotherm. We actually like the fancier term a bit better though, because her blood isn’t necessarily cold. Her body temperature can fluctuate with the environment