What is the role of arteries during blood volume loss?

• A. They contract to increase resistance and raise blood pressure
• B. They become rigid and stop blood flow
• C. They convert blood to lymph
• D. They thicken blood

Answer: (A)

When blood volume drops, arteries respond by constricting through vasoconstriction. The smooth muscle in arterial walls tightens under sympathetic stimulation, increasing systemic vascular resistance and helping to raise or maintain blood pressure so essential organs like the brain and heart continue to receive adequate blood flow. This reflex is triggered by baroreceptors sensing the fall in pressure and supported by hormonal signals that amplify the response. In other words, arteries pull the blood forward by narrowing, not by becoming rigid, and they don’t convert blood to lymph or thicken the blood. This constriction keeps perfusion up while the body works to restore volume.