Red Blood Cells vs. White Blood Cells: Key Differences Explained

Erythrocytes (Red blood cells)

- Biconcave, anucleate, non-motile

- Contain hemoglobin, appear pinkish-red

- Average diameter is 7-8 µm

- More abundant than WBCs

- 4.3-5.6 million/µL

- Produced in bone marrow

- Functions: Carries respiratory gases (O₂ & CO₂)

- Life span is 120 days

- Destroyed by the spleen and liver

Leukocytes (white blood cells)

- Variable shapes, nucleated, non-motile/motile

- Colorless

- Average diameter is 10-12 µm

- Less abundant than RBCs

- 4,000-11,000/µL

- Produced in bone marrow (myeloid), thymus (lymphoid), and lymph nodes (lymphoid)

- Function: Protect the body from infection, inflammation

- Life span: Varies from hours to years depending on the type

- Destroyed by the spleen and liver