Leukocytes/Thrombocytes

• 2 categories of leukocytes

  • agranulocytes (do not have visible granules)

    • lymphocytes

    • monocytes

  • granulocytes (have visible granules)

    • basophil

    • neutrophil

    • eosinophil

Granulocytes

• neutrophil

  • engulf and destroy foreign bacteria

  • most common leukocyte and more produced during infection

• Eosinophil

  • two-lobed nuclei

  • kill parasitic worms ingested in food

  • also, lessens allergic reactions

• Basophil

  • release histamines, which dilate blood vessels so other leukocytes can rush to an infection or allergen

Agranulocytes

• Lymphocyte

  • large, spherical nucleus

  • mostly found in lymph nodes, rather than the bloodstream

  • 2 types: T-cells and B-cells

• Monocyte

  • nucleus is kidney-shaped

  • when monocytes leave the blood and enter surrounding tissues, they become macrophages

    • macrophages attack and engulf viruses, parasites, and bacterial infections

Thrombocytes

• platelets

• made of tiny fragments of other cells

• responsible for clotting the blood when a vessels is broken