White Blood Cells

White Blood Cells

1. Neutrophils
   Neutrophil:

   - They are Highly phagocytic and have defensive function.
   - They increase in number, reach the inflammed tissue and engulf bacteria which invade the body.
   
   

2. Eosinophils
   Eosinophil :

   - They are related to allergy and hypersensitivity.
   - Their number increases in allergic conditions and in parasitic worm infestations.
   - They absorb histamine released in allergic conditions
   - They prevent the toxic effects of foreign proteins.
   - They are weak phagocytes. 
   
   

3. Basophils
   Basophil:

   - They store heparin, histamine, serotonin and bradykenin.
   - They secrete heparin.
   - They are related to allergy.
   - They are not phagocytic.
   
   

4. Lymphocytes
   Lymphocytes:

   - B-lymphocytes : responsible for humoral immunity.
   - T-lymphocytes : responsible for cell-mediated immunity.
   - Natural killer cells : they act as a defense against viral infections and destroy malignant cells.
   
   

5. Monocytes
   Monocytes:

   - They are highly phagocytic and they digest bacteria and dead neutrophils.
   - Macrophages engulf and kill bacteria.
   - They play an important role in cell-mediated immunity.
   - They secret interleukin-1 which stimulate growth of lymphocytes.