๐Ÿฉธ Chapter 534 ยท Anatomy and Function of the Spleen

Nelson Textbook of Pediatrics 22nd Edition | The spleen is the largest secondary lymphoid organ. White pulp: periarteriolar lymphoid sheaths (T cells) and germinal centers (B cells) โ†’ immune function. Red pulp: filtering system (cords of Billroth, splenic sinuses) โ†’ removal of senescent/abnormal RBCs, pitting of inclusions (Howell-Jolly bodies, Heinz bodies). Marginal zone: IgM memory B cells. Splenic dysfunction leads to Howell-Jolly bodies, pits on RBCs, increased risk of encapsulated bacterial sepsis (pneumococcus, meningococcus, Hib).

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๐Ÿ“‹ 30 Clinical Scenarios โ€” Spleen Anatomy & Function

๐Ÿ“‡ Highโ€‘Yield Review Cards (Spleen)

๐Ÿฉบ Clinical Scenarios: Splenic Function & Dysfunction

Select a presentation for pathophysiologic explanation.

๐Ÿ“‹ Clinical Implications of Splenic Dysfunction

๐Ÿ”‘ Key Principles โ€” Nelson Chapter 534
โ€ข Spleen functions: Immune (IgM memory B cells, opsonin production), filtering (RBC pitting, removal of senescent RBCs), reservoir (platelets, RBCs).
โ€ข Hyposplenism/Asplenia: Causes: sickle cell disease (functional asplenia), congenital asplenia (Ivemark syndrome), surgical splenectomy. Labs: Howell-Jolly bodies (nuclear remnants), Heinz bodies, pits on RBCs (phase microscopy).
โ€ข Overwhelming post-splenectomy infection (OPSI): Encapsulated bacteria (Streptococcus pneumoniae, Haemophilus influenzae type b, Neisseria meningitidis).
โ€ข Prevention: Vaccinations (PCV13, PPSV23, MenACWY, MenB, Hib) + prophylactic penicillin (at least until age 5 years, often lifelong).
โ€ข Accessory spleen (15%): May cause recurrence of ITP or hemolysis after splenectomy.

    โšก Reflex Prompts โ€” Clinical Decisions in Splenic Disorders

    ๐Ÿ“– Summary: Anatomy & Function of the Spleen โ€” Nelson Ch 534