Secondary Lymphoid Tissues Quiz

Secondary Lymphoid Tissues

• Comprise essential immune organs that facilitate immune responses and maintenance of immune cells.
• Include the spleen, lymph nodes, and various associated lymphoid tissues.

Spleen

• Regulates red blood cell circulation and manages their fate within the body.
• Contains germinal centers that develop in response to immune activity, similar to lymph nodes.
• The marginal zone (MZ) serves as a boundary between the blood and the spleen's white pulp, filled with specialized immune cells.
• MZ plays a vital role in trapping blood-borne pathogens, housing unique dendritic cells, macrophages, and marginal zone B cells.
• Naïve B and T cells stationed in the spleen encounter antigens, leading to their activation.
• Activated CD4⁺ T cells provide assistance to B cells and CD8⁺ T cells, prompting migration back to follicles to form germinal centers.
• Germinal center B cells can differentiate into memory or plasma cells and are capable of relocating to various tissues, including the bone marrow.

Other Secondary Lymphoid Tissues

• Lymph Nodes: Integral for filtering lymphatic fluid and serving as sites for immune cell activation.
• Mucus Associated Lymphoid Tissue (MALT): Includes lymph nodes, tonsils, and adenoids, involved in mucosal immunity.
• Gut Associated Lymphoid Tissue (GALT): Comprises Peyer's patches, mesenteric lymph nodes, and the appendix, essential for gut immunity.
• Skin Associated Lymphoid Tissue (SALT): Contributes to skin immune defense.
• Bronchus Associated Lymphoid Tissue (BALT): Focuses on respiratory tract immunity.