Question

Homeostatic systems maintain a steady-state set point over time using negative feedback. Which one of the following statement is NOT TRUE for stability of metabolic system:

Select one:

a. Metabolic systems that oscillate must have multiple control variables

b. Step changes in a controlled variable will return the system to its original state using negative feedback

c. Perturbations from steady state, either positive or negative, result in recovery reactions that return the system to its original state

d. A positive feedback system is stable over time, maintaining a steady state

Answer 1

• Homeostasis is the condition in which a system such as the human body is maintained in a more-or-less steady state
• Homeostasis is maintained at many levels.
• Maintenance of homeostasis usually involves negative feedback loops. These loops act to oppose the stimulus, or cue, that triggers them.
• The hallmark of a negative feedback loop is that it counteracts a change, bringing the value of a parameter—such as temperature or blood sugar—back towards it set point.
• Unlike negative feedback loops, positive feedback loops amplify the starting signal.

From above point it is clear that Perturbations from steady state, either positive or negative, result in recovery reactions that return the system to its original state. is not true. Because positive feedback amplifies the starting point, not stoping the positive point, and is not making the original system.