Question

Name the different types of leucocyte and state their functions

Answer 1

Leukocytes have nuclei and do not contain haemoglobin. The WBCs are classified as either granular or agranular leukocytes.

(a) Granular leukocytes (72 %) are:

• Neutrophils (70%) - These are smaller and evenly distributed and pale iliac in colour. The nucleus has two to five lobes. They responds to allergic reactions and have anti-histamine properties.
• Eosinophils (0.5%) - They contains eosinophilic granules and are usually multi lobed often S-shaped. They produce histamine and heparin.
• Basophils (0.5%) - They contains large basophilic granules, these are multi lobed granulocytes. They also produce histamine and heparin.

(b) Agranular leukocytes (28%) are of two type :

• Monocyte (4%) - These are 12-20 micrometer in diameter. The nucleus of a monocyte is usually kidney shaped or horse shoe shaped. They are basically perform phagocytic function by engulfing bacteria or foreign particle.
• Lymphocyte (24%) - The nucleus of lymphocyte is round and large. Lymphocytes produce antibodies to fight against any foreign particle.