The body has several fluids that are important for its defence: blood, lymph, and mucus. Blood is the body’s main defence fluid, and contains antibodies, proteins, and other components that fight off infections and other diseases. Lymph is a clear fluid that helps transport white blood cells throughout the body, helping to fight off infections and other diseases. Mucus is a thick fluid that lines the respiratory and digestive systems, helping to trap germs and other particles before they can enter the body. All of these fluids are important components of the body’s immune system, helping to protect it from disease and infection.