1. Stages of Development of Blood Cells
Dr. Sama ul Haque

2. Objectives Understand the composition of whole blood.
How to prepare a blood smear.
Describe the structure of Erythrocyte.
Enlist different types of leucocytes.
Explain the differentiation of myeloid and lymphoid stem cells.
Discuss the development of blood cells in red bone marrow.

3. Composition of Whole Blood

4. Preparing a Blood Smear

5. Blood Cells

6. Blood Cells

7. Erythrocyte

8. Normal Human Erythrocyte

9. Types of Human Leucocytes Neutrophils, eosinophils, and basophils have granules that stain specifically with certain dyes and are called granulocytes. Lymphocytes and monocytes are considered agranulocytes, even though they may show azurophilic granules (lysosomes), which are also present in other leukocytes.

10. Neutrophils Neutrophils can be identified by their multilobulated nuclei, with lobules held together by thin strands. With this feature the cells are often called polymorphonuclear leukocytes, or just polymorphs.

11. Eosinophils Eosinophils are about the same size as neutrophils but have bilobed nuclei and abundant coarse cytoplasmic granules. The cytoplasm is often filled with brightly eosinophilic specific granules, but also includes some azurophilic granules. (a): An eosinophil next to a neutrophil for comparison with its nucleus and granules. (b): Even with granules filling the cytoplasm, the two nuclear lobes of eosinophils are usually clear.

12. Basophils Approximately the same size as neutrophils and eosinophils, but have large, strongly basophilic specific granules which usually obstruct the appearance of the nucleus having two or three irregular lobes.

13. Lymphocytes
Lymphocytes are agranulocytes and lack the specific granules characteristic of granulocytes. (a): Small lymphocytes are slightly larger than the neighboring erythrocytes with spherical nucleus. (b): Medium lymphocytes are distinctly larger than erythrocytes. (c): Large lymphocytes, much larger than erythrocytes.

14. Monocytes Monocytes are large agranulocytes that circulate as precursors to macrophages and other cells of the mononuclear phagocyte system. Monocytes show their eccentric nuclei indented, kidney shaped, or U shaped.

15. Platelets Platelets are cell fragments 2–4 µm in diameter derived from megakaryocytes of bone marrow. Their primary function is to rapidly release the content of their granules upon contact with collagen to begin the process of clot formation and reduce blood loss from the vasculature. Platelets (arrows) are often found as aggregates.

16. Differentiation of Myeloid And Lymphoid Stem Cells
1. EPO– Erythropoietin
2. CSF– Colony
Stimulating Factor
3. GM-CSF–
Granulocyte+Macrophage
CSF
4. M-CSF– Macrophage CSF
5. G-CSF– Granulocyte CSF

17. Differentiation of Myeloid And Lymphoid Stem Cells

18. Development of Blood Cells in Red Bone Marrow

19. Thank You