Monocytes are agranulocytes, while the rest are granulocytes.
- Neutrophils, eosinophils, and basophils are granulocytes since they have cytoplasmic granules which can digest microorganisms.
- Lymphocytes and monocytes are agranulocytes since they lack granules in their cytoplasm.
Neutrophils are granular leukocytes and develop from the myeloid cell lineage within the bone marrow. They are the most abundant leukocyte type, making up 40-70% of those found in peripheral blood.
It is named so because they histologically stain with eosin, are granular leukocytes from the myeloid cell line within the bone marrow.
Basophils are granular leukocytes of myeloid lineage. They are 14-16µm in diameter and have a bi-lobed, S-shaped nucleus. Basophils circulate through the peripheral blood and have a lifespan of roughly 2 weeks.
Monocytes belong to the myeloid cell line within the bone marrow. They are primarily involved in the immune response against bacterial infection and makeup roughly 5-10% of all circulating leukocytes.