White Blood Cells (WBCs)

This lecture is about White Blood Cells (WBCs) presented by Rufia Abbas, she from Karachi, Sindh Pakistan.
For Video: https://www.youtube.com/watch?v=Nno1QH4tw2k

1. White Blood Cells Presented by Rufia Abbas 11/14/2022

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3. White Blood Cells White blood cells are the body cells which involve in defense mechanism & immunity system. These control and kill the pathogen or just neutralize the disease-causing parasite. The WBC count in a healthy individual is 4.5 to 10.5 x 10 3 per micro liter. They can increase or decrease in the disease conditions. They are also known as leucocytes. Leuco =white & cyte = cell 11/14/2022 3

4. Types of WBCs There are different types of WBC’s  divided based on their physical appearance, internal cell constituents and also staining requirements. They are studied using microscope by staining with suitable dyes According to their physical appearance under microscope they can be classified in to the following GRANULOCYTES [granule – beads) AGRANULOCYTES (cells without visible granules) 11/14/2022 4

5. AGRANULOCYTE Those cells which do not have visible granules in their cytoplasm under microscope come in this category. They have clear cytoplasm. They have non lobular nuclei . regular shape nuclei They are sometimes referred to as mononuclear leukocytes. Agranulocyte includes Lymphocytes    (20-25%) Monocytes           (3-8%) 11/14/2022 5

6. GRANULOCYTES: Those cells which show visible granules in their cytoplasm under microscope come in this category. They have multilobed nucleus. (irregular nucleus ) As a result they are also called polymorphonuclear (PMN) leukocytes. Their cytoplasm contains granules filled with enzymes and substances required for their function. Granulocytes includes: Eosinophils (2 -4 %) Basophils          (0.5-1%) Neutrophils      (60-70) 11/14/2022 6

7. Role and function of WBC in the body: white blood cells are immune cells. They provide defense or immunity to host body. This defense involves, a) Prevention of infection, b) Expulsion of disease causing agent from body and c) Even repair of damaged tissues. D) neutralization of aged cells These above function are not performed by all the WBC types. Instead, each cell type has a specific role in the body. 11/14/2022 7

8. GRANULOCYTE 11/14/2022 8

9. Neutrophils  They are part of innate immune defense. They are also known as phagocytes or phagocytic cells. They have cytoplasmic granules that stain a pale pink (neutral) color when stain with a dye known as “wright stain”. They eat up any pathogenic organisms or foreign substance. They concentrate in the individual organs like lungs during infection to combat and form pus. 11/14/2022 9

10. EOSINOPHILS They are WBCs with cytoplasmic granules that appear red when stained with Wright Stain. Also known as Acidophils because they take up the color of acidic dye eosin. Granules appear red because negatively charge eosin dye bind to their positively charge proteins present in granules. 11/14/2022 10

11. BASOPHILS WBCs with cytoplasmic granules that appear blue because they take up the color of basic dye “methylene blue” They are very low in number compared to all other WBC cells. They circulate in blood stream and search for allergens. They have receptor on their cell surface for Fc(constant fargment ) portion of IgE . 11/14/2022 11

12. AGRANULOCYTE 11/14/2022 12

13. Monocytes : These cell are called as second line of defense in the body. They form in macrophages once they reach tissues from the blood. Major cell that perform phagocytosis. They are phagocytes as well as antigen presenting cell (APC). APC is a cell that phagocytosed antigen and display some of its antigenic fragment on its surface. 11/14/2022 13

14. Lymphocyte Adaptive immunity cells types T-lymphocyte: T-Cell, B-Cell & NK. Small lymphocyte : T and B cell ( adaptive immunity cells) Large lymphocyte: Natural killer cell (NK) They have a large mono lobe nucleus and a small cytoplasmic region. No visible granules in cytoplasm. 11/14/2022 14

15. Reference Medical Microbiology & Immunology Book by Ernest Jawetz and Warren E. Levinson 11/14/2022 15