positive and negative feedback quick question

Hey

so I understand negative feedback as trying to come back to the original level e.g. if the temperature is increasing - negative feedback will try and decrease / increase the temp to bring it back to the original level (obv I'm really simplifying it here as I've only had a quick glance at it).

Examples of positive feedback would be things such as hyperthermia where you get further and further from the original temperature of the body...so does that mean temperature control can be used as an example of positive and negative feedback and we can't just say its one of the other?

Hey

so I understand negative feedback as trying to come back to the original level e.g. if the temperature is increasing - negative feedback will try and decrease / increase the temp to bring it back to the original level (obv I'm really simplifying it here as I've only had a quick glance at it).

Examples of positive feedback would be things such as hyperthermia where you get further and further from the original temperature of the body...so does that mean temperature control can be used as an example of positive and negative feedback and we can't just say its one of the other?

Negative feedback: A produces B. When the concentration of B increases it inhibits the production of more B by A.

Positive feedback: A produces B. When the concentration of B increases it stimulates the production of more B by A.

This is a definite misunderstanding of what positive/negative feedback are. Hyperthermia is a disease state - it is an example of failed thermoregulation.

Positive/negative feedback are two principles involved in homeostasis - of which thermoregulation is a part. Negative feedback can be thought of a "get it to the normal level" process, but defining it as such causes the misunderstanding that you have - the opposite process, positive feedback, isn't a mechanism that "get it away from normal level". Both processes are defined very simply in the post above mine. To give you examples:

Negative feedback: A produces B, B inhibits A.
You reabsorb lots of water from your kidneys, this decreases the ion concentration of your blood, your body detects this and releases ADH, ADH decreases water reabsorption.

Your blood pressure increases, sending a signal that causes vasodilation, this decreases blood pressure.

Positive feedback: A produces B, B enhances A.
Uterus begins contracting: this causes release of oxytocin: oxytocin causes uterus to contract more.

Nope.

Negative feedback is how you describe, only the change MUST CAUSE the REVERSION TO NORMAL conditions.

And this is such with positive feedback, but your example here isn't correct. Higher temperature doesn't cause further increase in body temp - other stuff does (namely interleukin-1). Hype en Ecosse has given some good examples.

Thanks - you really simplified it


Thanks a lot- also the examples really helped



Thank you