The primary function of the lymphatic system in humans is to maintain fluid balance and support the immune system. It achieves this by transporting lymph, a fluid containing white blood cells, proteins, and waste products, through a network of lymphatic vessels and nodes. The lymphatic system plays a crucial role in filtering pathogens and facilitating the movement of immune cells to sites of infection or injury. Additionally, it helps absorb and transport dietary fats from the digestive system. Overall, the lymphatic system is vital for protecting the body and maintaining homeostasis.