Imagine that you are about to give blood for the first time. While watching other donors around you, you become pale and have to sit down before you faint. Which vessels constricted to produce this nervous side effect?

Question

Quizplus · Accepted Answer

Arterioles are responsible for vasoconstriction, which reduces blood flow and can cause a decrease in blood pressure. This can lead to symptoms such as pallor and lightheadedness. Arteries, capillaries, venules, and veins do not have significant control over blood flow or vasoconstriction, so they are less likely to be involved in this type of nervous response.

Imagine That You Are About to Give Blood for the First