Name the granular and agranular WBCs. Give the major function of each type in the body.
The correct answer and explanation is :
Granular and Agranular White Blood Cells (WBCs) and Their Functions
White blood cells (WBCs), or leukocytes, are key components of the immune system and are categorized into granular and agranular types based on the presence of granules in their cytoplasm.
Granular WBCs (Granulocytes)
- Neutrophils – These are the most abundant WBCs, making up about 60-70% of all leukocytes. They are the first line of defense against infections and engulf pathogens through phagocytosis.
- Eosinophils – These cells play a major role in allergic reactions and parasitic infections. They release enzymes to combat multicellular parasites like helminths.
- Basophils – The least common WBCs, basophils release histamine and other chemicals during allergic reactions and inflammation, promoting vasodilation and attracting other immune cells.
Agranular WBCs (Agranulocytes)
- Lymphocytes – These include B cells, T cells, and natural killer (NK) cells. B cells produce antibodies, T cells help in cell-mediated immunity, and NK cells destroy virus-infected and cancerous cells.
- Monocytes – The largest WBCs, monocytes differentiate into macrophages and dendritic cells, which engulf pathogens and present antigens to lymphocytes for immune response.
Detailed Explanation (300 Words)
White blood cells (WBCs) are essential for protecting the body from infections and diseases. They are classified as granulocytes (which contain visible granules) and agranulocytes (which lack visible granules).
Granulocytes include neutrophils, eosinophils, and basophils. Neutrophils are the body’s primary defense mechanism, quickly responding to infections by engulfing and digesting pathogens. Eosinophils mainly combat parasites and regulate allergic responses, while basophils play a significant role in allergies by releasing histamine, which causes inflammation.
Agranulocytes include lymphocytes and monocytes. Lymphocytes are specialized WBCs responsible for adaptive immunity. B lymphocytes produce antibodies, while T lymphocytes help destroy infected cells and regulate immune responses. Monocytes differentiate into macrophages and dendritic cells, which act as scavengers, engulfing microbes and dead cells, and presenting antigens to activate lymphocytes.
Together, WBCs form a complex and highly coordinated immune system, ensuring protection against pathogens, abnormal cells, and foreign substances.