Lymphatic System: Key Concepts

Returning excess fluid from body tissues to the central venous system.

Lymphatic capillaries collect excess fluid, draining into collecting vessels, then trunks, and finally ducts (lymphatic and thoracic) that empty into subclavian veins.

The right lymphatic duct drains the right upper quarter of the body into the right subclavian vein. The thoracic duct drains the other three-quarters of the body into the left subclavian vein.

Transport of lipids from digested food, absorbed into lacteals in intestinal cells, then drained into lymphatic vessels and the thoracic duct.

Creation and maturation of lymphoid cells (B and T cells). B and T cells are created in the red bone marrow, but T cells mature in the thymus.

Areas where mature B and T cells congregate and initiate immune responses; examples include lymph nodes, tonsils, and MALT.

Located throughout the body along lymphatic vessels, these filter lymph before it re-enters the venous system and initiate an immune response if pathogens are present.

Act as secondary lymphoid structures in the mouth and nose, aiding in immune response.

Located in the gastrointestinal, respiratory, and urinary tracts, it monitors these tracts for pathogens and initiates an immune response if necessary.

The largest lymphoid tissue; it filters blood, monitoring for pathogens and microorganisms.