- It is largest secondary lymphoid organ.
- Spleen specializes in filtering blood and trapping blood-borne antigens.
- It can respond to systemic infections.
- The spleen is surrounded by a capsule that extends a number of projections into the interior to form a compartmentalized structure.
- They are of two types: a) Red pulp b)White pulp
a) Red pulp:
- Populated by macrophages & numerous red blood cells (erythrocytes).
- It is the site where old and defective RBC are destroyed and removed.
b) White pulp:
- Populated mainly by T-Lymphocytes.