Question

Which of the following processes is a positive feedback mechanism?

a. Temperature regulation
b. Blood pressure regulation
c. Blood sugar regulation
d. Thyroid regulation
e. Blood clotting

Answer 1

Blood clotting is an example of a positive feedback mechanism because it amplifies the response until the clot is large enough to stop the bleeding. Other processes like temperature, blood pressure, blood sugar, and thyroid regulation are examples of negative feedback loops, aiming to return the body to a normal state.

Step-by-step explanation:

Positive Feedback Mechanism

The process that is an example of a positive feedback mechanism is e. Blood clotting. Positive feedback loops amplify the initial stimulus, leading to an enhanced response. In the case of blood clotting, when an injury occurs and a blood vessel is damaged, platelets in the blood begin to stick to the site and to each other. This releases chemicals that attract more platelets and clotting factors, thus escalating the process until the clot is sufficiently large to stop the bleeding.

Other examples provided, such as temperature regulation, blood pressure regulation, blood sugar regulation, and thyroid regulation, typically involve negative feedback loops where the body works to negate or reverse a change, pushing the system back to its set point or normal range.

In contrast, scenarios like childbirth and lactation during nursing also exemplify positive feedback mechanisms. For instance, during childbirth, uterine contractions lead to increased contractions, which continue until the delivery of the baby.

Answer 2

The process of blood clotting is a positive feedback mechanism because it involves a response that enhances the original stimulus, leading to rapid amplification of the clotting process until the injury is sealed. The correct answer to the question is e. Blood clotting.

Step-by-step explanation:

The process of blood clotting is an example of a positive feedback mechanism. In a positive feedback loop, an initial stimulus produces a response that exaggerates or enhances the original change in conditions, rather than opposing it. This mechanism amplifies the effect of the stimulus.

During blood clotting, when a blood vessel is injured, substances called clotting factors are activated. These factors then cause additional clotting factors to activate, leading to a rapid cascade of events that result in the formation of a blood clot. This clot acts to seal the injury and prevent further blood loss. As clotting progresses, more and more clotting factors become involved, accelerating the process until the bleed is effectively stopped.

Other processes like temperature regulation, blood pressure regulation, blood sugar regulation, and thyroid regulation are typically controlled by negative feedback loops, which act to counteract changes from a set point in the body and restore balance.