Which type of feedback loop is responsible for maintaining water balance in the human body by regulating antidiuretic hormone (ADH) secretion?

• A. Feedforward loop
• B. Positive feedback loop
• C. Open loop
• D. Negative feedback loop

Answer: (D)

Verified step by step guidance

1. Understand the concept of feedback loops: Feedback loops are mechanisms used by the body to maintain homeostasis. Negative feedback loops work to reverse a change and bring the system back to its set point, while positive feedback loops amplify a change.
2. Identify the role of antidiuretic hormone (ADH): ADH is secreted by the posterior pituitary gland and helps regulate water balance by increasing water reabsorption in the kidneys, reducing urine output.
3. Analyze the mechanism of water balance regulation: When the body detects low water levels (high blood osmolarity), ADH secretion increases to conserve water. Conversely, when water levels are high (low blood osmolarity), ADH secretion decreases to allow more water to be excreted.
4. Determine the type of feedback loop involved: Negative feedback loops are responsible for maintaining homeostasis by counteracting changes. In this case, the secretion of ADH adjusts based on the body's water levels to restore balance, which is characteristic of a negative feedback loop.
5. Conclude that the correct answer is 'Negative feedback loop' because it is the mechanism responsible for regulating ADH secretion to maintain water balance in the human body.