Lesson 14: White Blood Cells

White Blood Cells Overview

• White blood cells (leukocytes) are classified into two main types:

  • Granulocytes

  • Neutrophils:

    • Most abundant (60% of WBCs)
    • Key role in immune defense against bacterial and fungal infections

  • Basophils:

    • Involved in allergic reactions and release histamine, leukotrienes, prostaglandins

  • Eosinophils:

    • Defense against parasites

  • Agranulocytes

  • Monocytes:

    • Involved in phagocytosis and release of cytokines
    • Present antigens to T-lymphocytes

  • Lymphocytes:

    • B-lymphocytes:
    • Responsible for humoral immunity (antibody production)
    • T-lymphocytes:
    • Responsible for cell-mediated immunity (do not produce antibodies)
    • Natural killer cells:
    • Limit spread of tumors and microbial cells; affected by opioids (concern for cancer recurrence)

Key Points on Degranulation

• Anaphylaxis involves degranulation of: basophils and mast cells (select two from the list).