Spleen

  • It is largest secondary lymphoid organ.
  • The spleen is a large, ovoid secondary lymphoid organ, situated at high in the left abdominal cavity. clip_image002
  • 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.

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