Why is the spleen considered a secondary lymphoid organ?

• A. It produces red blood cells in adults.
• B. It is involved in the maturation of T lymphocytes.
• C. It filters blood and provides an environment for immune responses.
• D. It is the primary site for B cell production.

Answer: (C)

Verified step by step guidance

1. Understand the role of primary and secondary lymphoid organs: Primary lymphoid organs are where lymphocytes are produced and mature, such as the bone marrow and thymus. Secondary lymphoid organs are where immune responses are initiated.
2. Identify the function of the spleen: The spleen is involved in filtering blood, removing old or damaged red blood cells, and providing an environment for immune responses.
3. Differentiate between the production and maturation of lymphocytes: The spleen does not produce lymphocytes; instead, it provides a site for immune cells to interact with antigens and mount an immune response.
4. Recognize the spleen's role in immune response: The spleen contains white pulp, which is rich in lymphocytes and is crucial for mounting an immune response to blood-borne pathogens.
5. Conclude why the spleen is a secondary lymphoid organ: Since the spleen filters blood and facilitates immune responses rather than producing or maturing lymphocytes, it is classified as a secondary lymphoid organ.