Question

(i) Mention the two distinguishing features of eosinophils.

1. (ii) Define granulocytes and agranulocytes.

Answer 1

Distinguishing features of Eosinophils:

1. The eosinophils are the type of granular white blood cells (WBCs) or leucocytes and are said to be the specialized immune structures.
2. They occupy about 2.3% of the total white blood cells and their count increases when an allergy occurs.
3. Eosinophils play an inevitable role in providing inflammatory responses by secreting antitoxins during allergic reactions.
4. The distinguishing feature of eosinophils is that they have a bilobed nucleus.
5. Another characteristic is that the eosinophils stain brick-red when treating them with acidic dyes like eosin.

Granulocytes:

1. The white blood cells (WBCs) or leucocytes that contain granules in the cytoplasm are called granulocytes.
2. Granulocytes have a regularly lobed nucleus.
3. Based on the dyes on which they stain, the granulocytes are divided into three categories:

1. Neutrophils
2. Eosinophils
3. Basophils

Neutrophils:

1. Neutrophils are the most abundant type of WBCs found in the blood.
2. They occupy about 62% of the total white blood cells.
3. The nuclei of neutrophils have 3 to 4 lobes.
4. Their granules stain pink color with neutral dyes.
5. The main function of neutrophils is phagocytosis.

Eosinophils:

1. Eosinophils are said to be specialized immune structures.
2. They occupy about 2.3% of the total white blood cells.
3. The nuclei of eosinophils have 2 lobes.
4. Their granules stain brick-red with acidic dyes.
5. They provide inflammatory responses by secreting antitoxins during allergic reactions.

Basophils:

1. Basophils are the third type of granulocytes.
2. They occupy about 0.4% of the total WBCs.
3. The nuclei of basophils are larger and not clearly lobed.
4. Their granules stain purple-black with basic dyes.
5. They release histamine and heparin to provide inflammation.

Agranulocytes:

1. The white blood cells (WBCs) or leucocytes that do not contain granules in their cytoplasm are called agranulocytes.
2. The agranulocytes are divided into two categories:

1. Lymphocytes
2. Monocytes

Lymphocytes:

1. Lymphocytes are the smallest type of WBCs that are part of the lymphatic system.
2. They occupy about 30% of the total leucocytes.
3. The lymphocytes have a single large nucleus.
4. The main function of lymphocytes is to produce antibodies to kill microbes.

Monocytes:

1. Monocytes are another type of WBCs that perform phagocytosis.
2. They occupy about 5.3% of the total WBCs.
3. The monocytes have a large kidney-shaped nucleus.
4. They play an essential role in transforming them into macrophages when an infection occurs to invade and ingest the foreign particles.