The systemic veins function by:

The systemic veins function by:

• A. Returning oxygenated blood to the heart
• B. Pumping blood to the lungs
• C. Returning deoxygenated blood back to the heart
• D. Providing oxygen to tissues

Answer: (C)

Systemic veins have the job of returning blood after it has delivered oxygen to body tissues, so the blood they carry is low in oxygen (deoxygenated) and high in carbon dioxide. This deoxygenated blood is brought back to the heart, entering the right atrium via the superior and inferior vena cavae, and then moves on to the lungs to be re-oxygenated. That’s why the correct statement is that systemic veins return deoxygenated blood back to the heart. They don’t pump blood to the lungs (that’s the heart and pulmonary circulation’s role) and they don’t provide oxygen to tissues (arteries do that by delivering oxygen-rich blood).

Systemic veins have the job of returning blood after it has delivered oxygen to body tissues, so the blood they carry is low in oxygen (deoxygenated) and high in carbon dioxide. This deoxygenated blood is brought back to the heart, entering the right atrium via the superior and inferior vena cavae, and then moves on to the lungs to be re-oxygenated. That’s why the correct statement is that systemic veins return deoxygenated blood back to the heart. They don’t pump blood to the lungs (that’s the heart and pulmonary circulation’s role) and they don’t provide oxygen to tissues (arteries do that by delivering oxygen-rich blood).