What physiological process does systemic circulation primarily support?

Systemic circulation is primarily responsible for transporting oxygen-rich blood from the heart to the rest of the body, delivering essential nutrients and other substances to various tissues and organs. As the blood travels through the systemic circulation, it supplies necessary nutrients that support cellular function, growth, and energy production.

While hormone distribution and waste removal are important processes, they are also supported by systemic circulation but are not its primary focus. Hormones released from endocrine glands travel through the bloodstream, often using systemic circulation for distribution, but the core function remains nutrient delivery. Waste removal can occur through venous return to the heart, but this aspect is generally managed by other systems, including the lymphatic system and kidneys, rather than being the main role of systemic circulation. Oxygen exchange primarily occurs in the pulmonary circulation, where oxygen is taken up in the lungs and carbon dioxide is released. Hence, the essence of systemic circulation aligns closely with nutrient transport, making it the correct answer.