1.1 negative feedback

8/13/2019 1.1 Negative Feedback

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Group 1:

1)Nadiah binti Yusof

2)Genevie Eleanor Ruby

3)Latifah binti Jalilul

4)Chai Siew Lian

5)Nurpaznin binti Jusoh


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Negative Feedback


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Overview of Negative FeedbackIn animals such as ourselves, the internal

environment of our bodies must have certainconditions within tolerable limits to continue the

healthy functioning of us.

This is done by a process called negativefeedback control, where various receptors and

effectors bring about a reaction to ensure thatsuch conditions remain favourable.


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Definition of Negative Feedback

The mechanism by which the body maintains

conditions within particular limits. The body willdo this by opposing a change that deviates from

the normal


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The Principle of Negative Feedback

Control


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Examples of Negative FeedbackControl

Regulation of body temperature

Regulation of blood sugar

Regulation of blood pressure


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Glucose is important for healthy functioning becauseit is required for the formation of ATP, the molecule ofenergy transfer in our bodies.

Two important hormones for blood glucose regulationare insulin and glucagon.

Insulin is secreted by beta cells while alpha cellssecrete glucagon. As the food we eat is broken down,our blood sugar rises due to the carbohydrates. Inorder to avoid serious problems such as kidney andcardiovascular damage, blood sugar levels have to bedecreased.

Mechanism of Blood Sugar

Regulation


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So, how does our body regulate our

blood glucose levels to maintainhomeostasis?


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Mechanism of Blood Sugar Regulation


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The internal mechanism for blood glucose regulation

is negative feedback.

As you can see from the figure, depending on

whether glucose levels are rising or falling, the body

has a different response.

When levels increase, the beta cells secrete insulin

which then converts glucose to glycogen so that

extra glucose can be stored restoring glucose levels

to a normal level. When levels fall, the alpha cells secrete glucagon

which converts stored glycogen to glucose

increasing levels back to normal.


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Benefits of Negative Feedback

Homeostasis has survival value because itmeans an animal can adapt to a changingenvironment. It can deal with the temperaturedifference you face when you step out your frontdoor.

The body will attempt to maintain a norm, thedesired level of a factor to achieve homeostasis.However, it can only work within tolerable limits,where extreme conditions can disable thenegative feedback mechanism

1.1 negative feedback

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