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?
A) Venules
B) Veins
C) Capillaries
D) Arterioles
E) Arteries

Question

Quizplus · Accepted Answer

Arterioles constrict in response to stress or fear, leading to decreased blood flow and potentially causing symptoms like paleness and fainting. This is part of the body's fight-or-flight response, regulated by the autonomic nervous system.

Imagine That You Are About to Give Blood for the First