More than half of the lymph is derived from which organs?

The liver and intestines play a significant role in lymph production, particularly because they are involved in the digestion and absorption of nutrients. The liver, as a central organ in metabolism, processes many substances that enter the body and produces a significant amount of lymph as it filters blood and other fluids. The intestines also contribute notably to lymph production, particularly through the absorption of dietary fats, which are transported in the lymphatic system as chyle.

The other organs listed do not contribute as significantly to lymph production. While the heart and lungs are critical to the circulatory and respiratory systems, they are not prominent sources of lymph. The spleen participates in the immune response and filtering blood but is not a primary producer of lymph. Similarly, though the pancreas plays a key role in digestion, it does not generate a significant amount of lymph like the liver and intestines do. The kidneys are essential for filtering blood and producing urine but also do not have a primary role in lymph production. Therefore, the liver and intestines are the correct integrative organs associated with the generation of the majority of lymph in the body.