Final answer:
Lymphatic organs like the lymph nodes and spleen have a protective capsule made of dense connective tissue, which is important for their function in the immune system.
Step-by-step explanation:
Lymphatic organs generally have a capsule consisting of dense connective tissue. The primary lymphoid tissues, which include the bone marrow and thymus, and the secondary lymphoid tissues such as the spleen, lymph nodes, and areas of diffuse lymphoid tissue, all exhibit this structural trait. Lymph nodes, for example, are encapsulated by a tough layer of connective tissue and are compartmentalized by trabeculae. They play a crucial role in the immune system by housing areas called germinal centers rich in B and T lymphocytes and by facilitating antigen presentation via specialized macrophages and dendritic cells.