Blood and lymph are the two circulating fluids in the animal body. Blood belongs to the circulation system whereas lymph belongs to the lymphatic system. Blood contains pigments which carry oxygen. Therefore, blood can be found in different colors in different types of organisms. But, lymph is a colorless fluid. Blood is composed of red blood cells, white blood cells, platelets and a fluid called plasma. Lymph is composed of white blood cells and a watery fluid. Both blood and lymph possess a circulatory function as well as an immune function. The main difference between blood and plasma is that blood circulates inside blood vessels whereas lymph circulates inside lymphatic vessels.
