Which statement best describes a lymph node?

Which statement best describes a lymph node?

• A. It is where B cells mature
• B. It removes old RBCs
• C. It collects fluid from the tissues
• D. It is considered a primary lymphoid organ

Answer: (C)

Lymph nodes are secondary lymphoid organs that organize immune responses by filtering lymph—the fluid that drains from tissues—and providing a site where immune cells can meet antigens. Lymphatic vessels carry interstitial fluid from tissues into the node, where immune cells such as B and T cells can examine it, become activated, and proliferate. B cells mature in the bone marrow, not in lymph nodes, and T cells mature in the thymus. Lymph nodes are not primary lymphoid organs; primary ones are where immune cells originate and mature (bone marrow and thymus). Removing old red blood cells is a function of the spleen, not lymph nodes. So the best-described role of a lymph node is that it collects fluid from the tissues (lymph).

Lymph nodes are secondary lymphoid organs that organize immune responses by filtering lymph—the fluid that drains from tissues—and providing a site where immune cells can meet antigens. Lymphatic vessels carry interstitial fluid from tissues into the node, where immune cells such as B and T cells can examine it, become activated, and proliferate. B cells mature in the bone marrow, not in lymph nodes, and T cells mature in the thymus. Lymph nodes are not primary lymphoid organs; primary ones are where immune cells originate and mature (bone marrow and thymus). Removing old red blood cells is a function of the spleen, not lymph nodes. So the best-described role of a lymph node is that it collects fluid from the tissues (lymph).