Final answer:
Fluid that includes lymphocytes, plasma cells, white blood cells, neoplastic cells, and bacteria can be found in the lymph node. The lymphatic system transports and filters this fluid, which engages with the immune cells for a protective response against pathogens.
Step-by-step explanation:
Fluid that may include lymphocytes, plasma cells, white blood cells, neoplastic cells, and bacteria can be found in the lymph node. The lymphatic system is composed of lymphoid tissues, including the lymph nodes which house these cells, and operates as part of the immune system. As lymph circulates through the lymph nodes, it filters and interacts with the immune cells present in these nodes, including B and T lymphocytes, plasma cells, and macrophages, that are crucial for the immune response.
B and T lymphocytes, which include B cells maturing in the bone marrow and T cells maturing in the thymus gland, are responsible for the adaptive immune response. Plasma cells are differentiated B cells that produce antibodies. The combination of these cells forms a defense network against pathogens. Lymphatic vessels transport the lymph fluid that contains these cells along with other substances.