Which term describes the system consisting of all the blood vessels?

• A. The Vascular System
• B. The Circulatory System
• C. The Lymphatic System
• D. The Immune System

Answer: (A)

Think of the body’s network of tubes that carry blood: those are the arteries, veins, and capillaries—the pathways that make up the vascular system. This term is the precise description of all the blood vessels themselves, without including the heart or the blood as a substance. The circulatory or cardiovascular system is a broader name that can include the heart as the pump and the blood, but when the question focuses on the vessels, the vascular system is the most accurate fit. The lymphatic system involves lymph vessels and lymph fluid, not blood vessels, and the immune system is about immune cells and defenses, not the vascular network. So the vascular system is the correct term.