Advanced Dental Admission Test (ADAT)

Which of the following is a function of thromboxanes?

1. Inhibit platelet aggregation

2. Cause vasodilation

3. Increase platelet aggregation and cause vasoconstriction

4. Stimulate gastric protection

The correct answer is: Increase platelet aggregation and cause vasoconstriction

Thromboxanes are eicosanoids derived from arachidonic acid and play a significant role in hemostasis and vascular physiology. One of their primary functions is to promote platelet aggregation, which is critical for the formation of blood clots. Thromboxane A2, the most notable thromboxane, is released from activated platelets and stimulates the activation and aggregation of additional platelets at the site of injury, thereby enhancing the clotting process. Additionally, thromboxanes exert vasoconstrictive effects, which help to reduce blood flow to the area of injury, promoting localized clotting and minimizing blood loss. Thus, the accurate option correctly encapsulates these dual roles by stating that thromboxanes increase platelet aggregation and cause vasoconstriction. Understanding this function is vital in the context of thrombosis and related cardiovascular diseases, where thromboxane's role becomes particularly significant in pathological conditions.