The primary function of the lymphatic system is to maintain fluid balance in the body, particularly by collecting and returning excess interstitial fluid to the bloodstream. Additionally, it plays a crucial role in the immune system by transporting lymph, which contains lymphocytes—white blood cells that help the body fight infections and diseases. The lymphatic system also aids in the absorption of fats and fat-soluble vitamins from the digestive system through specialized lymphatic vessels called lacteals. Overall, this complex network of vessels and nodes is vital for both fluid homeostasis and immune defense.