Which circulatory pathway is involved when the right side of the heart pumps blood to the lungs?

The correct answer is the pulmonary pathway, which is specifically responsible for transporting deoxygenated blood from the right side of the heart to the lungs. In the pulmonary circulation, the right ventricle pumps blood through the pulmonary arteries to the lungs, where carbon dioxide is exchanged for oxygen. After the blood is oxygenated in the lungs, it returns to the left side of the heart via the pulmonary veins, ready to be pumped into the systemic circulation to supply the rest of the body with oxygen-rich blood.

Understanding this pathway is crucial for recognizing how blood flow is maintained and how gas exchange occurs in the lungs, which is vital for oxygenating the blood and removing carbon dioxide. The other pathways listed serve different functions: the systemic pathway delivers oxygenated blood to the body, the coronary pathway supplies blood to the heart muscle itself, and the portal pathway involves the circulation of blood from the gastrointestinal tract to the liver.