Which of the following is NOT a major part of the circulatory system?

The pancreas is an organ involved primarily in the digestive system and endocrine functions, producing insulin and digestive enzymes. It does not play a direct role in the circulatory system, which is primarily concerned with transporting blood throughout the body. In contrast, the heart, arteries, and veins are all essential components of the circulatory system. The heart pumps blood, arteries carry oxygen-rich blood away from the heart, and veins return deoxygenated blood back to the heart. Understanding the distinct functions of these components clarifies why the pancreas is not a major part of the circulatory system.