What organs are part of the circulatory system?

The circulatory system, also known as the cardiovascular system, is primarily responsible for the transport of blood, nutrients, gases, and waste products throughout the body. It consists of several key components, among which are the heart, blood, and blood vessels.

The heart functions as the central pump that propels blood throughout the body, ensuring that all tissues receive oxygen and nutrients while removing waste products. Blood serves as the transport medium, carrying these essential components between the heart and various body tissues. Meanwhile, blood vessels, including arteries, veins, and capillaries, form a network that facilitates the flow of blood to and from the heart and all parts of the body.

In contrast, the other choices reference different organ systems. The lungs are part of the respiratory system, and while they work closely with the circulatory system to oxygenate blood, they are not part of the circulatory system itself. The kidneys and ureters are components of the urinary system, which is responsible for waste elimination and fluid regulation. Lastly, the brain and nerves fall under the nervous system, which coordinates bodily function but does not pertain directly to blood circulation. Understanding these distinctions is crucial in recognizing the specific components that make up the circulatory system.