White Blood Cells

By comparison to RBCs, WBCs have a nucleus, but no hemoglobin, and are divided into granular and agranular leukocytes, as shown here. RBCs outnumber WBCs by a ratio of 700:1. The normal range for WBCs is between 5,000 - 10,000 cells/microliter.

Description	Granular Leukocytes
Eosinophil: Responds to allergic and parasitic infection Represent 4% WBC concentration.
Basophil: Promotes inflammation and allergic reactions. Represents 1% WBC concentration.
Neutrophil: Chief phagocytes respond to acute infection. Represents 65% WBC concentration.

Description	Agranular Leukocytes
Lymphocytes: Converted to antibody forming cells. Represents 23% WBC concentration.
Monocyte: Secondary phagocytes Represent 5% WBC concentration.

Leukocytosis is an increase in the number of WBCs above 10,000 cells/microliter in response to infection, anesthesia, surgery and excercise.

Leukopenia Is a decrease in WBC below 5,000 cells/microliter resulting from radiation, shock, chemotherapy.

Chemotaxis - Phagocytic attraction to antigens resulting from the release of certain chemicals.