1. Nadia Goodwin & Missy Walker
Blood and Bone Marrow
Histology SSN
November 18, 2004
Presented by:
Nadia Goodwin & Missy Walker

2. Formed Elements of the Blood

3. Peripheral Blood: Erythrocytes
RBCs constitute the largest number of cells in the blood
Biconcave discs
NO NUCLEUS
Contain Hemoglobin

4. Peripheral Blood: Platelets
Derived from Megakaryocytes in bone marrow – formed from small bits of Megakaryocyte cytoplasm
Function in blood clotting

5. Peripheral Blood: Leukocytes
GRANULOCYTES
Neutrophils
Basophils
Eosinophils
AGRANULOCYTES
Lymphocytes (T and B cells)
Monocytes (Macrophages)

6. Peripheral Blood: Leukocytes
GRANULOCYTES
Neutrophils
Basophils
Eosinophils

7. Granulocytes: Neutrophils
Most numerous WBC in blood
Multilobed nucleus
Granules:
Azurophilic granules
Specific granules
Function
1st wave of cells in acute inflammation; can phagocytose bacteria

8. Granulocytes: Basophils
Rare!
Lobulated nucleus often obscured by granules
Dark Blue Granules
Hydrolytic enzymes, heparin sulfate, histamine, SRS
Function
Role in hypersensitivity and anaphylaxis

9. Granulocytes: Eosinophils
Bilobed nucleus
Bright pink Granules
Arginine rich major basic protein, peroxidase, histaminase, arylsulfatase
Function:
Important in allergic rxns, parasitic infections, and phagocytosis of Ab-Ag complexes

10. Agranulocytes: Monocytes
Largest WBCs in blood smear
Migrate through blood to the tissues; once in tissues they differentiate into phagocytes (macrophages)

11. Agranulocytes: Lymphocytes
About size of RBCs
Function
Main functional cells of adaptive immune system
T cells
B cells

12. Questions Which of the following cell types would be expected to be increased in number with a bacterial infection? Viral? Parasitic?

14. RBC Development Watch for trends!

15. Proerythroblast Biggest in lineage
Large central nucleus with one or two nucleoli
Basophilic cytoplasm b/c ribosomes
Look for Golgi ghost

16. Basophilic Erythroblast
Smaller than proerythroblast
Checkerboard nucleus (heterochromatic)
Intense basophilia (lots of ribosomes!)

17. Proerythroblast vs Basophilic Erythroblast

18. Polychromatophilic Erythroblast
Smaller than basophilic erythroblast
Smaller intensely heterochromatic nucleus
Purple/lilac cytoplasm mix of basophilia from ribosomes and growing eosinophilia from hemoglobin
LAST MITOTIC STAGE!

19. Normoblast Smaller than polychromatophilic erythroblast
Small, compact, intensely staining nucleus that is getting ready to be extruded
Eosinophilic cytoplasm due to abundant hemoglobin

20. Reticulocyte Immature RBC that has polyribosomes
Appear as polychrom-atophilic erythrocyte on blood smear
When stained with a special (supravital) stain  Reticulocyte

21. Erythrocyte
Smallest
Eosinophilic due to hemoglobin
NO NUCLEUS!

22. Erythropoiesis

24. Development of Granulocytes

25. What are the Granulocytes?
These are cells of the immune system (White Blood Cells) that contain vesicles. The vesicle contents vary among cell lines and stain differently.
Neutrophils (polymorphonuclear or PMN cells)
Eosinophils
Basophils

26. Trend of Development Larger to smaller
Azure granules to specific granules
Round nucleus to altered shape nucleus
Granulocyte Lineage:
Myeloblast → Promyelocyte → Myelocyte → Metamyelocyte → Band → Granulocyte
(Erythroid: Proerythroblast →Basophilic erythroblast → Polychromatophilic
erythroblast → Normoblast → Reticulocyte → Erythrocyte)

27. Myeloblast
Prominent nucleoli

28. PROmyelocyte Details Golgi ghost
Can’t distinguish type of granulocyte yet
Eccentric nucleus
Don’t confuse with proerythroblast or basophilic erythroblasts

29. Myelocyte Last stage in which mitosis can occur
Begin to see who’s a neutrophil, who’s an eosinophil (who’s a basophil)
Golgi ghost

30. Neutrophilic Myelocyte vs
Eosinophilic Myelocyte

31. METAmyelocyte nucleus changing shape, not spherical
Soooo No more mitosis

32. Band Cell Immature granulocyte
Elongated nucleus of nearly uniform width; horseshoe/U-shaped

33. Finally . . .

34. Myeloblast – no granules capable of
mitosis
Promyelocyte – azurophilic granules
Mylocyte – specific granules
Metamylocyte – specifc granules nucleus
changes shape
Band cell – (PMN only) specific granules
Mature Granulocyte – specific granules

35. Compare what you see . . .

36. Megakaryocyte Huge Platelets form from invaginations of this
Multilobular nucleus

37. Megakaryocyte

39. Don’t Worry, Be Happy!