Endocrine: Feedback Systems

[Laraine]

Hey everyone,

So I'm pretty sure that feedback systems are mostly negative except for oxytocin and LH right? My new anatomy teacher is telling us that "every feedback has a positive and negative. The reason for this is that with every reaction there is an opposite reaction. Meaning if something has been turned on to make a change there needs to be something that turns it off. This also hold true for oxytocin- it has both because just as the body requires its release it also need it to be regulated and turned off".

I think he is wrong.

It is negative because if a variable changes then the system responds by making the opposite change. In positive feedback if the variable changes the system responds by continuing the change( to a point). ie: LH stimulates estrogen secretion which enhances LH secretion which stimulates estrogen leading to the LH surge which triggers ovulation.

What have you been taught?

Thanks everyone :)

[Esme12, ASN, BSN, RN]

I am just a student in anatomy right now so I am no expert either. But, I do agree with you. The only positive feedback systems I can think of are ovulation, childbirth, and blood clotting. I've never had a teacher explain it the way your teacher did and I've taken several biology classes. For example, why would our body use a positive feedback loop to regulate blood sugar levels? It is regulated by negative feedback; if it had a positive feedback loop you would have diabetes, right? Unless he means that in this case the positive feedback loop is when you eat and your blood sugar continues to go up?? But I don't think you could count that as positive feedback because your body isn't automatically eating; you decide when you want to eat. Maybe he's not completely wrong, but at the very least confusing. I'm not sure, just trying to help you think through it. Good luck!

Wow I have never heard that explained like that....positive and negative feedback........so, If I understand this correctly..... yes you make the decision to eat but the body sends you signals (hunger pains) (negative) that tell you you are hungry and must eat (positive) and when you are "full" it sends you a signal to let you know it's time to stop......the malfunction of this is obesity.....so I guess I agree that every every system has positive and negative impulses to keep the body in balance.

The entire body is a system of checks and balances to maintain homeostasis.

[Laraine]

One day I hope to be happy to be finished school as well, but I imagine there are nurses and doctors who make mistakes too, and what's the best way to handle it? One class I just blurted out "that's not right!" Tack is not one of my forte's. I guess this is a lesson I need to learn: what to do in the face of ineptitude with authority.

A happy day to all!