b

Eosinophil

Peripheral Blood

Erythrocytes = RBCs NO NUCLEUS Contain hemoglobin

Platelets

Leukocytes = WBCs Granulocytes Neutrophils = PMNs = “polys” Eosinophils = “eos” Basophils = “basos” Agranulocytes Lymphocytes = T and B cells B cells  plasma cells Monocytes  Macrophages (M Φ )

Granulocytes PMNEosBaso PMN

Neutrophils Numerous Multilobed nucleus Azurophilic & Specific granules Phagocytose bacteria

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

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

Monocytes Largest WBCs in blood smear Migrate through blood to the tissues; once in tissues they differentiate into phagocytes (macrophages, osteoclasts)

Lymphocytes About size of RBCs Function Adaptive immune system T & B cells

Questions Which of the below cell types would increase in number with a bacterial infection? Viral? Parasitic?

Bone Marrow Smear

Erythropoesis

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

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

Proerythroblast vs Basophilic Erythroblast

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!

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

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

Erythrocyte Smallest Eosinophilic due to hemoglobin NO NUCLEUS!

Review

Granulopoesis

Ross Fig 9-18 p. 235

Development of Granulocyte (focus on PMN)

What are Granulocytes? WBCs that contain specific granules Granule contents vary between cell types and stain differently Neutrophils (“polys” or PMNs) Eosinophils Basophils

Trend of Development Larger  smaller Azure granules  specific granules Round nucleus  altered shape nucleus Granulocyte Lineage: Myeloblast → Promyelocyte → Myelocyte → Metamyelocyte → Band → Granulocyte

Myeloblast Prominent nucleoli

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

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

Neutrophilic Myelocyte vs Eosinophilic Myelocyte

METAmyelocyte nucleus changing shape, not spherical No more mitosis

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

Finally...

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

Review

Compare what you see...

Megakaryocyte Huge Platelets form from invaginations of this Multilobular nucleus

Monocyte

Don’t Worry, Be Happy! Animations: User: library Password: cumed Click on the “Peripheral Blood” lesson