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negative/positive feedback loops

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negative/positive feedback loops

Postby scaredofbiology » Fri Feb 01, 2008 6:22 am

this is my first time on this thing so i have no idea on how this works but i have a question! okay so the question is what are some examples of negative and positive feedback loops dealing with homeostasis?? if you could reply asap that would be great :D
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Postby MichaelXY » Fri Feb 01, 2008 5:46 pm

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Postby mith » Fri Feb 01, 2008 5:53 pm

Positive feedback is what you get when you put your microphone next to a speaker.
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Re: negative/positive feedback loops

Postby Darby » Fri Feb 01, 2008 9:11 pm

You could make a case for inflammation being a positive feedback system. A lot of defensive responses are sort-of positive feedback...
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Re: negative/positive feedback loops

Postby Jammerz » Sat Feb 02, 2008 12:42 am

Nearly every system in the body is a negative feedback loop; there are very few positive feedback loops in the body, and one example of positive feedback is childbirth.
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Postby MrMistery » Sun Feb 03, 2008 6:46 pm

My professor always used to give the example of the ovarian cycle as containing both negative and positive feedback in hormone secretion levels. This is also a reason why those hormones are so hard to remember :lol:
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Postby Darby » Thu Feb 07, 2008 5:28 pm

I've been teaching that feedback is mostly negative, but it seems like immunological reactions - big responses to small stimuli, responses need to be held back from overload - are mostly positive feedback.
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Postby MrMistery » Sun Feb 24, 2008 8:34 pm

Feedback is mostly negative in most body functions, when discussing regulating levels of various signals or compound concentrations. However, when discussing imunological responses lots of positive feedback needs to be involved in order to mount specific attacks...
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Postby Cat » Mon Feb 25, 2008 2:08 am

Glucagon and Insulin are great examples.
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Postby Darby » Mon Feb 25, 2008 9:03 pm

For those not familiar with the example, both of those hormones (which interact mostly with liver cells that store carbohydrates) are in feedback loops with sugar - sugar levels too high, insulin release brings them down; too low, glucagon brings them up.
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Postby Darwin420 » Fri Mar 07, 2008 1:16 am

Negative feed back example: When you are cold, body muscles contract, hair on body stands errect. Body is doing everything in its power to maintain its inner temperature.

That was one example my professor gave me.
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Postby MrMistery » Sat Mar 08, 2008 10:32 am

The body hair erecting is an evolutionary relicve. It doesn't really do anything to us short-haired apes.
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