Question

Why are leucocytes classified as granulocytes and agranulocytes? Name each cell and mention its functions.

Answer 1

White blood corpuscles are colourless. They are nucleated cells. They are found in the bone marrow, spleen, thymus, and lymph nodes. They are grouped into two categories:

1. Granulocytes: They contain granules in their cytoplasm. Their nucleus is irregular or lobed. The granulocytes are of three types:

• Neutrophils: They are large in size and have a 2 – 7 lobed nucleus. Their numbers are increased during infection and inflammation.
• Eosinophils: It has a bilobed nucleus. Their numbers increases during conditions of allergy and parasitic infections. It brings about the detoxification of toxins.
• Basophils: Basophils have a lobed nucleus. They release chemicals during the process of inflammation.

2. Agranulocytes: Granules are not found in the cytoplasm of these cells. Thy is of two types:

• Lymphocytes: Lymphocytes produce antibodies during bacterial and viral infections.
• Monocytes: They are the largest of the leucocytes and are amoeboid in shape. They are phagocytic and can engulf bacteria.