Which four components make up the circulatory system?

Which four components make up the circulatory system?

• A. Heart, arteries, veins, and blood
• B. Heart, arteries, veins, and lungs
• C. Heart, lungs, kidneys, and blood
• D. Heart, veins, capillaries, and arteries

Answer: (B)

The circulatory system is fundamentally comprised of structures that facilitate the movement of blood throughout the body and the transportation of necessary substances. The four primary components are the heart, arteries, veins, and blood. The heart acts as the central pump, circulating blood through various pathways. Arteries carry oxygen-rich blood away from the heart to the tissues, while veins return deoxygenated blood back to the heart. Blood itself is the medium that transports oxygen, nutrients, hormones, and waste products, making it an integral part of the system. Other options include components that do not specifically make up the circulatory system. The mention of lungs refers to the respiratory system, which is involved in gas exchange and works in tandem with the circulatory system, but does not directly constitute its main components. The kidneys are part of the urinary system and are concerned with filtration and waste removal rather than blood circulation. Capillaries are part of the vascular system and are critical for nutrient and gas exchange; however, when considering the core components, they do not replace the primary distinctions made between arteries and veins. Thus, the correct answer accurately identifies the essential building blocks of the circulatory system.

The circulatory system is fundamentally comprised of structures that facilitate the movement of blood throughout the body and the transportation of necessary substances. The four primary components are the heart, arteries, veins, and blood.

The heart acts as the central pump, circulating blood through various pathways. Arteries carry oxygen-rich blood away from the heart to the tissues, while veins return deoxygenated blood back to the heart. Blood itself is the medium that transports oxygen, nutrients, hormones, and waste products, making it an integral part of the system.

Other options include components that do not specifically make up the circulatory system. The mention of lungs refers to the respiratory system, which is involved in gas exchange and works in tandem with the circulatory system, but does not directly constitute its main components. The kidneys are part of the urinary system and are concerned with filtration and waste removal rather than blood circulation. Capillaries are part of the vascular system and are critical for nutrient and gas exchange; however, when considering the core components, they do not replace the primary distinctions made between arteries and veins.

Thus, the correct answer accurately identifies the essential building blocks of the circulatory system.