Question

Damaged tissue releases chemicals that activate platelets and stimulate the formation of blood clots. Which of the following predictions about the activity of platelets best describes a positive feedback mechanism

Answer 1

Hello! I figured your question was lacking its options so I went online to find them and here they are:

A. Activated platelets release chemicals that  inhibit blood clot formation.

B. Activated platelets release signaling  molecules that inhibit cell division in  damaged tissue.

C. Activated platelets constrict the blood  vessels, stopping blood flow.

D. Activated platelets release chemicals that  activate more platelets.

Answer:

The correct answer is: D) Activated platelets release chemicals that  activate more platelets.

Explanation:

Positive feedback is a mechanism in which a stimulus triggers an intensification of this same stimulus.

When a tissue is damaged, the platelets participate in a process called platelet adhesion that consists of contacting and sticking to the collagen fibers of the connective tissue under the damaged endothelial cells. This platelet adhesion activates the platelets and makes them grow projections to contact and interact with one another, while releasing substances to activate other nearby platelets. The accumulation and the attachment of large numbers of platelets ultimately form a platelet plug.