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positive and negative feedback - Coggle Diagram
positive and negative feedback
Negative
: mechanisms detect departure from a set point norm and act to restore the steady state.
negative feedback acts to counteract departures from steady state.
most physiological systems achieve homeostasis through negative feedback, negative is movement away from a steady state is detected and triggers a mechanism to counteract change
negative feedback has a stabilising effect, dampening variations from a set point and returning internal conditions to a steady state .
it counteracts a change, bringing the value of a parameter—such as temperature or blood sugar—back towards it set point
when a system's output acts to reduce or dampen the processes that lead to the output of that system, resulting in less output.
Negative feedback serves to reduce an excessive response and to keep a variable within the normal range.
Negative feedback loops control body temperature and the blood glucose level.
Positive
: results in the escalation of a response to a stimulus. It causes system instability and is used where a particular outcome or resolution is required.
very few physiological processes involve positive feedback because such mechanisms are unstable. ( if left unchecked they can be dangerous and fatal)
amplify their initiating stimuli, in other words, they move the system away from its starting state.
Positive feedback mechanisms are designed to accelerate or enhance the output created by a stimulus that has already been activated.
Positive feedback mechanisms are designed to push levels out of normal ranges.
positive feedback loop is ended when a natural resolution is reached
There is a stabilising effect, dampening variations from a set point and returning internal conditions to a steady state
Very few physiological processes involve positive feedback because the mechanisms are unstable , they can also be fatal and dangerous
Homeostasis
: refers to the (relatively) constant physiological state of the body despite fluctuations in the external environment
Any change in the environment to which an organism responds is called a stimulus.
To maintain homeostasis, the body must detect stimuli through receptors, process the sensory information, and respond to it via effectors. the responses provide new feedback
Receptor
: detects change and sends a message to the control centre
control centre
: receives the message and coordinates a response . sends an output message to an effector.
Effector
: responds to the output from the control centre
most enzymes in the body denature above 40 degrees, if the body's internal enviroment reaches this temperature for any prolonged time it can result in death
In negative feedback systems, the response reverses the original stimulus, but in positive feedback systems, the response enhances the original stimulus.