IMMUNOLOGY

Detailed explanation-1: -Spleen: A sac-like mass of lymphoid tissue with protective roles in both the immune and lymphatic systems.

Detailed explanation-2: -Lymphoid tissue has several different structural organizations related to its particular function in the immune response. The most highly organized lymphoid tissues are in the thymus and lymph nodes, which are well-defined encapsulated organs with easily identifiable architectures.

Detailed explanation-3: -Lymph nodes are small, bean-shaped masses of lymphatic tissue along lymph vessels. They store lymphocytes and filter waste, bacteria and damaged cells (including cancer cells) from lymph.

Detailed explanation-4: -The lymphatic system is part of the immune system. It keeps body fluid levels in balance and defends the body against infections. Lymphatic (lim-FAT-ik) vessels, tissues, organs, and glands work together to drain a watery fluid called lymph from throughout the body.