Lymphatic System Organs: A Comprehensive Overview

The lymphatic system comprises primary and secondary lymphoid organs:

Primary Lymphoid Organs (Lymphocyte Development)

• Bone marrow – B-cell maturation (mammals); HSC niche.
• Thymus – T-cell selection/maturation; involutes after puberty.

Secondary Lymphoid Organs (Immune Activation)

• Lymph nodes – filter lymph; B-cell follicles, T-cell paracortex.
• Spleen – filters blood; white pulp (lymphoid), red pulp (RBC filtration).
• MALT (Mucosa-Associated Lymphoid Tissue)
• Tonsils (palatine, tubal, lingual, pharyngeal/adenoid)
• Peyer's patches (ileum)
• Appendix
• Bronchus-associated (BALT), gut (GALT)

Vascular Components

• Lymphatic capillaries → collecting vessels → trunks (thoracic duct, right lymphatic duct) → subclavian veins.

This network enables immune surveillance, fluid homeostasis, and lipid transport.