Correct option is B
The incorrect statement is (b). Peripheral lymph nodes are involved in immune responses, but they are not directly responsible for immune responses to blood-borne pathogens. Instead, lymph nodes are primarily involved in filtering lymph (which is derived from interstitial fluid) and facilitating immune responses to tissue-derived pathogens. Blood-borne pathogens are more likely to be dealt with by other components of the immune system, such as the spleen, which specializes in filtering blood.
Information Booster:
- Lymph nodes are strategically placed throughout the body to filter lymph, a fluid that comes from tissues. They contain specialized areas where immune cells, such as T cells and B cells, interact with antigen-presenting cells like dendritic cells to initiate an immune response.
- The spleen, rather than lymph nodes, plays a major role in immune responses to blood-borne pathogens, filtering pathogens and initiating an immune response from blood-borne antigens.
Additional Information:
- Fibroblast reticular cells (statement 1): This is a correct statement. Fibroblast reticular cells form a network of fibers in the lymph node, creating a conduit system that helps guide the movement of immune cells such as lymphocytes.
- T cells encounter antigen on dendritic cells in the paracortex (statement 3): This is correct. The paracortex of the lymph node is where T cells encounter antigen-presenting dendritic cells, which present antigens they have processed, initiating the adaptive immune response.
- B cells in follicles (statement 4): This is also correct. B cells are found in the follicles of the lymph nodes, which are specialized regions where B cells undergo activation and differentiation, often forming germinal centers during immune responses.
