Question

which of the following is an example of positive feedback? release of insulin by the pancreas in response to increases in blood sugar after a meal. platelets adhering at a break in a blood vessel and release chemicals that attract even more platelets. parathyroid hormone stimulating osteoclast activity when blood calcium levels fall below normal. muscle shivering when core body temperature drops.

Answer 1

Platelets attracting more platelets to a site of injury is an example of positive feedback, as it amplifies the response to the stimulus.

Therefore, the correct answer is: option "platelets adhering at a break in a blood vessel and release chemicals that attract even more platelets."

Step-by-step explanation:

The platelets continue to amass, more of the chemicals are released and more platelets are attracted to the site of the clot. The positive feedback accelerates the process of clotting until the clot is large enough to stop the bleeding.

An example of positive feedback is when platelets adhere at a break in a blood vessel and then release chemicals that attract even more platelets.

Platelet plug formation is considered a positive feedback process because ADP and VWF levels are successively increased as more and more platelets activate to form the plug. This is a situation where the response to a stimulus amplifies the process, which is characteristic of positive feedback loops.

In contrast, negative feedback involves reversing the direction of a stimulus, like the secretion of insulin by the pancreas in response to increased blood sugar levels.