* Lymph nodes: These small, bean-shaped organs are scattered throughout the body and filter lymph fluid, trapping foreign substances and presenting them to immune cells. They also house large numbers of lymphocytes (a type of leukocyte).
* Spleen: This organ filters blood, removing old or damaged red blood cells and storing platelets and white blood cells. It also plays a role in immune responses.
* Thymus: This gland, located in the chest, is primarily active in childhood. It produces and matures T lymphocytes, a type of leukocyte that plays a crucial role in cell-mediated immunity.
* Bone marrow: This soft, spongy tissue found inside bones is the primary site of production for all blood cells, including leukocytes.
While not considered a dedicated storage organ, the bloodstream also carries a significant number of leukocytes, ready to be transported to areas of infection or inflammation.
