Which of the following is an example of negative feedback?
A) During birthing contractions, the hormone oxytocin is released and acts to stimulate further contractions.
B) When blood glucose concentration increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases.
C) When a baby is nursing, suckling leads to the production of more milk and a subsequent increase in the secretion of prolactin, which in turn stimulates lactation.
D) After a blood vessel is damaged, signals are released by the damaged tissues that activate platelets in the blood. These activated platelets release chemicals that activate more platelets.

Question

Quizplus · Accepted Answer

Negative feedbacks involve a response that works to counteract a stimulus or disturbance, in order to maintain or restore a stable state or set point. In option B, blood glucose concentration is the stimulus, and insulin release is the response that works to decrease glucose concentration. As glucose concentration decreases, the rate of insulin production and release is also reduced, thus providing negative feedback to prevent excessive lowering of blood glucose. Option A, C, and D describe positive feedback mechanisms, which involve a response that amplifies or reinforces a stimulus or deviation from a set point, leading to an enhanced or accelerated change in the same direction.

Which of the Following Is an Example of Negative Feedback