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HELP!!Need examples of neg & pos feedback on homeostasis

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HELP!!Need examples of neg & pos feedback on homeostasis

Postby noclue » Sat Feb 11, 2006 12:41 am

can some one please help me im taking A&P 1 for the first time and i dont understand nothing. i have an exam coming up soon and i really need to understand the difference between negative and positive feedback on homeostasis and what are some examples!!!!!!!!!!!!!!!!!!!!!!! :(
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Postby cardiorrhexis » Sat Feb 11, 2006 4:17 am

Negative feedback is when you have a change in your body which impairs homeostasis and your body corrects it. (Overheating then sweating, Sweating, then drinking)

Positive feedback is when the change is pushed farther in the altering direction. (A mild seizure progressing to status epilepticus)

More Examples:

Negative feedback: Compensatory stage of shock....increased heart rate to perfuse all tissues.

Positive Feedback: Decompensatory stage of shock progressing to Terminal stage of shock...heart rate gets slower and the body temp falls....etc.
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Postby Dr.Stein » Mon Feb 13, 2006 10:26 am

Negative and positive feedback 2in1 example for homeostasis:
Regulation of ovarium cycle by FSH and LH ---> estrogen and progesteron 8)

Try to understand this figure. It gives you all information. If you don't get the point, I'll explain it later :)

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Postby Navin » Mon Feb 13, 2006 11:18 am

Look at this scenario: Meerkats sunbathe in the morning but avoid sunbathing in the afternoon when it is too hot.

Is this an example of negative feedback?
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Postby Dr.Stein » Mon Feb 13, 2006 11:33 am

:?
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Postby cardiorrhexis » Tue Feb 14, 2006 1:56 am

Navin wrote:Look at this scenario: Meerkats sunbathe in the morning but avoid sunbathing in the afternoon when it is too hot.

Is this an example of negative feedback?


It would depend on the meerkat's physiological response to the sunbathing.

Heat exhaustion- Positive Feedback
Thermoregulation- Negative Feedback


:D
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Postby zenith_beth » Thu Feb 16, 2006 9:41 am

As a general rule:
Negative feedback : deviation form the normal, and then back to the normal
Positive feedback : deviation from the normal, then deviation keeps increasing instead of returning to normal. (positive deviation is rather rare in nature)
wizzie :-)
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Postby MrMistery » Thu Feb 16, 2006 6:52 pm

An example of positive feedback are the reactions that take place in blood clotting
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Postby Dr.Stein » Mon Feb 20, 2006 6:40 am

Blood clotting is a cascade reaction. Which reactions do you mean? :?
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negative and positive feedback

Postby sham » Fri Mar 10, 2006 3:18 am

I read about -ve and +ve feedback from books and different books gave different answers. When there is any change from the optimum condition,
1) -ve feedback will activate sequence of actions that will tend to restore the system back to normal.
2) -ve feedback is a process that inhibit a detector/regulator once conditions return to normal, thereby maintaining the stability of the system.
Which one is correct? Any help?
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Postby cardiorrhexis » Sat Mar 11, 2006 5:23 pm

Both...the statements are basically saying the same thing.
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Postby MrMistery » Sat Mar 11, 2006 6:44 pm

@Dr.Stein
All of them, until the end, cause reaction activates the next and so on and so forth..
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