Components of a negative feedback loop
Identify the four components of a negative feedback loop and explain what would happen if secretion of a body chemical controlled by a negative feedback system became too great.
Four Components of a Negative Feedback Loop:
A negative feedback loop consists of four key components:
- Sensor: This detects a change in the body's internal environment (e.g., temperature, blood sugar, hormone levels).
- Control Center: This receives the signal from the sensor and interprets it.
- Effector: This responds to the control center's instructions to bring the internal environment back towards its normal range.
- Inhibitor: This monitors the effector's action and signals the control center when the desired level is reached, stopping the effector's activity.
- Overshoot and Correction:
- The effector initially overreacts, leading to a temporary overshoot beyond the desired level.
- The inhibitor detects the overshoot and signals the control center.
- The effector's activity is reduced or stopped, eventually bringing the level back to the normal range.
- Diminished Sensitivity:
- The excessive secretion might overwhelm the system, causing desensitization of the sensor or the control center.
- As a result, the system becomes less responsive to future changes, leading to dysregulation and potential health problems.
- Receptor Blockade:
- In some cases, the excess chemical might directly block its own receptors, preventing their response to normal levels of the chemical.
- This creates a state of functional deficiency, even though the actual levels of the chemical are high.
- System Breakdown:
- In extreme cases, the excessive secretion might overload the system's ability to respond, leading to breakdowns in the control mechanisms.
- This can result in severe consequences, depending on the specific chemical and its function in the body.
- In the case of blood sugar regulation, excess insulin secretion could lead to hypoglycemia (low blood sugar).
- Excessive thyroid hormone secretion can cause hyperthyroidism, with symptoms like anxiety and weight loss.
- In rare cases, overproduction of cortisol (stress hormone) can lead to Cushing's syndrome, characterized by weight gain, high blood pressure, and other problems.