What are the three major components of the cardiovascular system?

The three major components of the cardiovascular system include the heart, blood, and blood vessels. The heart acts as the pump that circulates blood throughout the body, ensuring that oxygen and nutrients are delivered to tissues and waste products are removed. Blood serves as the transport medium that carries oxygen, nutrients, hormones, and waste products between different body parts. Blood vessels, which include arteries, veins, and capillaries, function as the plumbing system that directs blood flow to and from the heart and throughout the body. This triad works synchronously to maintain the body's circulation and overall health.

In contrast, the other options either inaccurately represent the components of the cardiovascular system or focus on unrelated structures such as alveoli and lungs, which are part of the respiratory system rather than the cardiovascular system.