Understanding Leukocytes: Types, Functions & Roles in Immunity

1). Neutrophils

* Most abundant leukocytes (50-70% of total WBC count)

* First line of defense against bacterial and fungal infections

* Short lifespan (12-24 hours)

* Phagocytic and release antimicrobial substances

2). Lymphocytes

* Involved in immune response

* B lymphocytes produce antibodies

* T lymphocytes mediate cell-mediated immunity

* Long-lived cells (several years)

3). Monocytes

* Phagocytic cells

* Differentiate into macrophages and dendritic cells

* Play a role in inflammation and tissue repair

4). Eosinophils

* Involved in defense against parasitic infections

* Release toxic substances that can damage parasites

* Also involved in allergic reactions

5). Basophils

* Least abundant leukocytes (less than 1% of total WBC count)

* Involved in allergic reactions and inflammation

* Release histamine and other inflammatory mediators

6). Platelets

* Not technically leukocytes, but are included here because they play a role in the immune response

* Involved in blood clotting and wound healing

* Release factors that can activate inflammation and attract immune cells