White Blood Cells & Their Mechanisms

Vocabulary flashcards covering granulocytes, agranulocytes, their functions, and specialized mechanisms.

What are Granulocytes?

A group of white blood cells with visible cytoplasmic granules; includes neutrophils, eosinophils, and basophils.

What are Neutrophils?

Most abundant granulocytes; phagocytize bacteria and some fungi at sites of inflammation.

What is a Respiratory Burst?

Neutrophil process that metabolizes oxygen to form hydrogen peroxide and bleach, killing engulfed microbes.

What are Defensins?

Antimicrobial peptides in neutrophil granules that insert into phagocytosed bacteria membranes, causing lysis.

What are Eosinophils?

Granulocytes specialized to attack parasitic worms in intestinal or respiratory mucosa by releasing digestive enzymes.

What are Digestive Enzymes (in Eosinophils)?

Granule contents released onto parasite surfaces, degrading and destroying large worms that cannot be phagocytized.

What are Basophils?

Least common granulocytes; granules contain histamine that is released after binding immunoglobulin E, promoting inflammation.

What is Histamine?

Inflammatory chemical stored in basophils and mast cells that vasodilates blood vessels and attracts other leukocytes.

What are Mast Cells?

Tissue-resident cells that release histamine, amplifying inflammatory responses and recruiting white blood cells.

What are Agranulocytes?

White blood cells lacking visible granules; includes lymphocytes and monocytes.

What are Lymphocytes?

Agranulocytes central to adaptive immunity; subdivided into T cells and B cells.

What are T Lymphocytes (T Cells)?

Directly attack virus-infected and cancerous cells as part of the cellular immune response.

What are B Lymphocytes (B Cells)?

Differentiate into plasma cells that secrete antibodies (immunoglobulins) into the bloodstream.

What are Monocytes?

Largest agranulocytes; circulate in blood and migrate into tissues where they become macrophages.

What are Macrophages?

Differentiated monocytes that phagocytize viruses, intracellular bacterial parasites, and chronic infection agents like tuberculosis, and activate lymphocytes.