how does the structure of arterioles make them important in maintaining blood pressure?

Answer 1

An arteriole is a small diameter blood vessel that extends and branches out from an artery and leads to capillaries.

Arterioles have thin muscular walls (usually only one to two layers of smooth muscle) and are the primary site of vascular resistance

This means blood pressure in the arteries supplying the body is a result of the interaction between the cardiac output (the volume of blood the heart is pumping per minute) and the vascular resistance, usually termed total peripheral resistance

Answer 2

they have thick muscular walls of elastic fibres and connective tissue which enables them to expand and contract as the heart beats, pushing blood out of the heart and into the arteries and arterioles. they expand and contract to match the beats of the heart, and this is what is felt as a pulse. the elastic fibres create a recoil mechanism.