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 the primary vessels that constrict to regulate blood flow and blood pressure, which can lead to fainting due to reduced blood flow to the brain.

Imagine That You Are About to Give Blood for the First