Final answer:
Arterioles are significant in terms of resistance of blood flow because they are the site of greatest resistance in the entire vascular network. Their small lumen and the regulation of their diameter through vasoconstriction and vasodilation are key factors in slowing down blood flow and regulating blood pressure.
Step-by-step explanation:
Arterioles are significant in terms of resistance of blood flow because they are the site of greatest resistance in the entire vascular network. Despite their small size, arterioles slow down the flow of blood from arteries due to their small lumen, causing a substantial drop in blood pressure.
The diameter of arterioles can be regulated by neural and chemical controls, leading to vasoconstriction or vasodilation. These mechanisms play a crucial role in the distribution of blood flow and regulation of blood pressure.