Heme 01: Lab On Hematopoiesis And Blood

Front 1

What is hematopoiesis / hemopoiesis?

Back 1

Formation and development of various types of blood cells and other formed elements

Front 2

Where does hematopoiesis take place in the adult?

Back 2

Red Bone Marrow present in skull, vertebrae, ribs, sternum, ilia, and proximal epiphyses of some long bones

Front 3

What replaces the red bone marrow in bony cavities where hematopoiesis does not take place?

Back 3

Yellow Bone Marrow (infiltrated w/ fat)

Front 4

What does hematopoiesis begin with?

Back 4

Pluripotent hematopoietic stem cells (HSCs)

Front 5

What do the progenitor cells from HSCs develop?

Back 5

Colony Forming Units (CFUs) that generate a given type of blood cell

Front 6

By what process are RBCs formed?

Back 6

Erythropoiesis

Front 7

What are the goals of Erythropoiesis?

Back 7

Form a cell which is:
- Small to circulate easily
- Contains abundant hemoglobin for gas exchange
- Biconcave to maximize surface area for gas exchange

Front 8

What happens to the color of the cytoplasm in Erythropoiesis?

Back 8

Change from Blue (polyribosomes, Hb mRNAs) to Red (protein, Hemoglobin)

Front 9

What are the precursors of RBCs during Erythropoiesis that we should be able to identify?

Back 9

1. Proerythroblast
2. Polychromatophilic Erythroblast
3. Orthochromatophilic Erythroblast
4. Reticulocyte
5. Erythrocyte

Front 10

Proerythroblast:
- Stage
- Cell size
- Nucleus
- Cytoplasm

Back 10

- Stage: 1st
- Cell size: large (>2x size of RBC)
- Nucleus: large (~80% cell volume), round, central, prominent nucleolus
- Cytoplasm: basophilic (dark/royal blue) d/t presence of polyribosomes (Hb mRNA)

Front 11

Polychromatophilic Erythroblast:
- Stage
- Cell size
- Nucleus
- Cytoplasm

Back 11

- Stage: 2nd
- Cell size: medium (1.5x size of RBC)
- Nucleus: small, round, condensed chromatin
- Cytoplasm: grayish blue

Front 12

Orthochromatophilic Erythoblast:
- Stage
- Cell size
- Nucleus
- Cytoplasm

Back 12

- Stage: 3rd
- Cell size: small (slightly larger than mature RBC)
- Nucleus: small, round, eccentrically located, very condensed chromatin
- Cytoplasm: cytoplasm staining identical to that of mature RBC

Front 13

Retiuclocyte:
- Stage
- Cell size
- Nucleus
- Cytoplasm

Back 13

- Stage: 4th
- Cell size: cannot be distinguished from mature RBC
- Nucleus: cannot be distinguished from mature RBC
- Cytoplasm: cannot be distinguished from mature RBC

**Distinguishable from RBCs when stained w/ a supravital dye (eg, cresyl blue) because residual polyribosomes stain blue **

Front 14

What kind of cell is this? How can you tell?

Back 14

Proerythroblast

- Stage: 1st
- Cell size: large (>2x size of RBC)
- Nucleus: large (~80% cell volume), round, central, prominent nucleolus
- Cytoplasm: basophilic (dark/royal blue) d/t presence of polyribosomes (Hb mRNA)

Front 15

What kind of cell is this? How can you tell?

Back 15

Polychromatophilic Erythroblast

- Stage: 2nd
- Cell size: medium (1.5x size of RBC)
- Nucleus: small, round, condensed chromatin
- Cytoplasm: grayish blue

Front 16

What kind of cell is this? How can you tell?

Back 16

Orthochromatophilic Erythroblast

- Stage: 3rd
- Cell size: small (slightly larger than mature RBC)
- Nucleus: small, round, eccentrically located, very condensed chromatin
- Cytoplasm: cytoplasm staining identical to that of mature RBC

Front 17

What kind of cell is this? How can you tell?

Back 17

Reticulocyte:
- Distinguishable from RBCs when stained w/ a supravital dye (eg, cresyl blue) because residual polyribosomes stain blue

Front 18

How do you distinguish a reticulocyte from a fully mature erythrocyte?

Back 18

- Stain w/ a supravital dye (eg, cresyl blue)
- Residual polyribosomes stain blue

Front 19

What product is being synthesized by polyribosomes in cells in early stages of erythrocyte production?

Back 19

Hemoglobin

Front 20

Why is the cytoplasm changing color as the cells in the erythropoietic series differentiate?

Back 20

- Increase in Hemoglobin protein content leads to increased red staining
- Decrease in polyribosome (Hb mRNA) content leads to decreased blue staining

Front 21

How might iron deficiency affect morphology of erythrocytes?

Back 21

- Results in RBCs which are microcytic (smaller than normal)
- Exhibit hypochromasia (less Hb leads to decreased redness in RBCs)
- They tend to have staining only at periphery of cell d/t increased central pallor

Front 22

At which stage of development do the cells in the erythropoietic series lose their miotic ability?

Back 22

Early normoblasts may divide, but reticulocytes which lack nuclei are obviously post-mitotic

Front 23

If reticulocytes are found in the peripheral blood, does that indicate a pathological condition?

Back 23

- No, reticulocytes normally complete their maturation during the first 24-48 hours in circulation

- Excessive reticulocytes in peripheral blood is indicative of certain anemias especially hemolytic anemia, subacute hemorrhage, or ascent to high altitude

Front 24

Erythropoietin is a glycoprotein hormone that promotes development of erythroid progenitor cells by inhibiting programmed cell death. What tissue normally produces erythropoietin?

Back 24

Kidney (and liver)

Front 25

What are the precursors of neutrophils during Granulopoiesis that we should be able to identify?

Back 25

1. Myeloblast
2. Promyelocyte
3. Myelocyte
4. Metamyelocyte
5. Band / Stab Cell
6. Segmented Neutrophil

Front 26

Myeloblast:
- Stage
- Cell size
- Nucleus
- Cytoplasm

Back 26

- Stage: 1
- Cell size: large
- Nucleus: large, round, occupies the majority of the cell volume, delicate chromatin, prominent nucleoli
- Cytoplasm: thin rim of light blue cytoplasm

Front 27

Promyelocyte:
- Stage
- Cell size
- Nucleus
- Cytoplasm

Back 27

- Stage: 2
- Cell size: large, larger than a myeloblast
- Nucleus: large, round, delicate chromatin, prominent nucleoli
- Cytoplasm: abundant, heavily granulated by primary granules which obscure the nucleus

Front 28

Myelocyte:
- Stage
- Cell size
- Nucleus
- Cytoplasm

Back 28

- Stage: 3
- Cell size: large
- Nucleus: not indented
- Cytoplasm: specific granules present

Front 29

Metamyelocyte:
- Stage
- Cell size
- Nucleus
- Cytoplasm

Back 29

- Stage: 4
- Cell size: smaller than myelocytes
- Nucleus: kidney-shaped / indented (<1/2 of diameter)
- Cytoplasm: pink granules

Front 30

Band / Stab Cell:
- Stage
- Cell size
- Nucleus
- Cytoplasm

Back 30

- Stage: 5
- Cell size: approximately same as mature cell
- Nucleus: horseshoe-shaped / deeply indented (>1/2 of diameter)
- Cytoplasm: pink granules

Front 31

Mature Neutrophil:
- Stage
- Cell size
- Nucleus
- Cytoplasm

Back 31

- Stage: 6
- Cell size: mature size
- Nucleus: multiple nuclear lobes (3-5) separated by thin nuclear filament, called a "segment"
- Cytoplasm: pink granules

Front 32

What kind of cell is this? How can you tell?

Back 32

Myeloblast

- Stage: 1
- Cell size: large
- Nucleus: large, round, occupies the majority of the cell volume, delicate chromatin, prominent nucleoli
- Cytoplasm: thin rim of light blue cytoplasm

Front 33

What kind of cell is this? How can you tell?

Back 33

Promyelocyte

- Stage: 2
- Cell size: large, larger than a myeloblast
- Nucleus: large, round, delicate chromatin, prominent nucleoli
- Cytoplasm: abundant, heavily granulated by primary granules which obscure the nucleus

Front 34

What kind of cell is this? How can you tell?

Back 34

Myelocyte

- Stage: 3
- Cell size: large
- Nucleus: not indented
- Cytoplasm: specific granules present

Front 35

What kind of cell is this? How can you tell?

Back 35

Metamyelocyte

- Stage: 4
- Cell size: smaller than myelocytes
- Nucleus: kidney-shaped / indented (<1/2 of diameter)
- Cytoplasm: pink granules

Front 36

What kind of cells are this? How can you tell?

Back 36

Band / Stab Cells

- Stage: 5
- Cell size: approximately same as mature cell
- Nucleus: horseshoe-shaped / deeply indented (>1/2 of diameter)
- Cytoplasm: pink granules

Front 37

What kind of cell is this? How can you tell?

Back 37

Mature Segmented Neutrophil

- Stage: 6
- Cell size: mature size
- Nucleus: multiple nuclear lobes (3-5) separated by thin nuclear filament, called a "segment"
- Cytoplasm: pink granules

Front 38

What is the pattern of maturation of eosinophils and basophils?

Back 38

Similar way as neutrophils (all granulocytes)

1. Myeloblast (same for all)
2. Promyelocyte
3. Myelocyte
4. Metamyelocyte
5. Stab Cell
6. Eosinophil or Basophil

Front 39

How common are eosinophils vs basophils in bone marrow? Blood?

Back 39

- Eosinophils are more commonly encountered in bone marrow
- Basophils are rarely encountered in normal bone marrows

- Both are more common in blood

Front 40

Monocytes:
- Size
- Cytoplasm
- Nucleus

Back 40

- Size: large (2-3x RBC)
- Cytoplasm: abundant grey/blue cytoplasm w/ variably present, delicate pink granules which may be difficult to see in BM
- Nucleus: reniform / kidney-bean shaped or folded nucleus, no nucleoli

Front 41

Where are monocytes more easily identified?

Back 41

Blood by their abundant cytoplasm

Front 42

What kind of cell is this? How can you tell?

Back 42

Monocyte:

- Size: large (2-3x RBC)
- Cytoplasm: abundant grey/blue cytoplasm w/ variably present, delicate pink granules which may be difficult to see in BM
- Nucleus: reniform / kidney-bean shaped or folded nucleus, no nucleoli

Front 43

Lymphocytes:
- Size
- Cytoplasm
- Nucleus

Back 43

- Size: smallest nucleated cell in BM, roughly same as RBC
- Cytoplasm: scanty pale blue cytoplasm
- Nucleus: high nuclear to cytoplasmic ratio, uniformly condensed chromatin, no nucleoli

Front 44

What kind of cell is this? How can you tell?

Back 44

Lymphocyte

- Size: smallest nucleated cell in BM, roughly same as RBC
- Cytoplasm: scanty pale blue cytoplasm
- Nucleus: high nuclear to cytoplasmic ratio, uniformly condensed chromatin, no nucleoli

Front 45

Where do T cells mature? Where do they seed?

Back 45

- Mature in thymus
- Seed blood and lymphoid organs

Front 46

Where do B cells mature? What are their progenitor cells called?

Back 46

- Mature in bone marrow
- Progenitor cells are called Hematogones

Front 47

What are Hematogones?

Back 47

B cell progenitor cells

Front 48

What is the term for the formation of platelets?

Back 48

Thrombopoiesis (platelets aka thrombocytes)

Front 49

The CFU which produces platelets gives rise to what cells?

Back 49

Megakaryocytes

Front 50

Megakaryocytes:
- Size
- Nucleus
- Cytoplasm

Back 50

- Size: large (up to 100 µm diameter)
- Nucleus: single, multi-lobated
- Cytoplasm: pink/gray, resembling platelets

Front 51

What kind of cell is this? How can you tell?

Back 51

Megakaryocyte

- Size: large (up to 100 µm diameter)
- Nucleus: single, multi-lobated
- Cytoplasm: pink/gray, resembling platelets

Front 52

What is a routine site for bone marrow biopsies?

Back 52

Iliac Crest

Front 53

What can you see on a bone marrow core biopsy?

Back 53

- Bone trabeculae (bright pink, thin, contain few osteocytes)
- Adipose tissue (large, clear vacuoles)
- Hematopoietic elements (other purple cells)

Front 54

How do you determine the bone marrow cellularity?

Back 54

Estimate the relative percentage of hematopoietic cells to fat

Front 55

What does the bone marrow cellularity vary with? How can you estimate what it should be?

Back 55

- Varies with age
- Very general rule: Normal Cellularity = 100 - Age

Front 56

What are the two parts of blood?

Back 56

- Formed elements (including cells and platelets)
- Plasma

Front 57

What does plasma consist of?

Back 57

- 90% water
- Electrolytes (Na+, Cl-, K+, PO4-, HCO3-)
- Glucose
- Amino Acids
- Immunoglobulin
- Complement Proteins
- Steroids
- Clotting Factors

Front 58

What is the term for the color intensity of normal RBCs? What determines the intensity?

Back 58

Normochromatic (directly related to amount of hemoglobin)

Front 59

What is the term for decreased color staining intensity of RBCs?

Back 59

Hypochromasia

Front 60

What is the term for increased color staining intensity of RBCs? What other feature?

Back 60

Hyperchromasia (also have lack of central pallor)

Front 61

In the correct viewing areas, most of the RBCs have a pale staining center. Why?

Back 61

- RBCs have a biconcave shape
- Center of RBCs stains pale because there is less material in this thin part

Front 62

What is the function of the RBC's biconcave shape?

Back 62

Maximizes the surface to volume ratio facilitating gas exchange

Front 63

What cytoskeletal elements maintain the erythrocyte's shape?

Back 63

Spectrin, Actin, Ankyrin

Front 64

What is the term for RBCs with variation in cell size?

Back 64

Anisocytosis

Front 65

What is the term for RBCs with variation in cell shape?

Back 65

Poikilocytosis

Front 66

Based on the shape of this erythrocyte, can you identify this blood disorder? Cause?

Back 66

Sickle Cell Disease - result of a hereditary hemoglobinopathy / structurally abnormal hemoglobin

Front 67

What symptoms would you expect to find in a patient with this abnormality?

Back 67

Patients w/ severe Sickle Cell Disease have:
- Severe anemia (cells are fragile and lyse)
- Vaso-occlusive complications (membranes adhere to endothelium causing narrowing of small vessels which traps sickled cells, leads to vascular occlusion, and ischemic tissue damage (painful crises)
- Chronic hyperbilirubinemia (large amounts of bilirubin in blood, manifests as jaundice)

Front 68

Are nuclei visible in mature erythrocytes?

Back 68

No

Front 69

What effect does not having a nucleus have on a mature erythrocyte?

Back 69

RBCs have a limited life span of approx. 120 days in circulation

Front 70

What does it mean if a patient has increased reticulocytes in their peripheral blood?

Back 70

Indicates an increased demand for erythrocytes

Front 71

What conditions might produce the premature release of reticulocytes from BM into peripheral blood?

Back 71

Reticulocytes may appear in blood as a result of:
- Hemorrhage → loss of RBCs
- Anemia → loss of RBCs
- Ascent to high altitude → increased O2 demand

Front 72

What is the size of dried RBCs?

Back 72

7 µm

Front 73

What are the types of granules in leukocytes? How does their presence determine the type of leukocyte?

Back 73

- Non-specific (primary, azurophilic)
- Specific (secondary)

- Granulocytes (neutrophils, eosinophils, and basophils) have non-specific AND specific granules
- Monocytes and Lymphocytes lack specific granules but may contain non-specific granules

Front 74

Mature Neutrophils:
- Size
- Proportion of WBCs
- Nuclei

Back 74

- Size: 10 µm (slightly larger than RBCs)
- Proportion of WBCs: 30-70%
- Nuclei: several lobes (3-5) connected by thin filaments

Front 75

How do neutrophils differ if they are from females? Why?

Back 75

- Females may have neutrophils with nuclear lobes that have a drumstick-shaped nuclear appendage
- Nuclear appendage is the inactivated X chromosome (Barr body)

Front 76

Who has neutrophils with this appearance? Why?

Back 76

Females
- Nuclear appendage is the inactivated X chromosome (Barr body)

Front 77

What is the color of the neutrophil granules / cytoplasm?

Back 77

- Neutrophilic granules do not stain w/ either basic or acidic dyes
- Similar to color of erythrocyte cytoplasm

Front 78

What kind of granules are in Neutrophils? How do they differ? Similar?

Back 78

- Non-specific (primary) granules are fewer in number in normal granulocytes
- Specific (secondary) granules are more numerous

- Both contain enzymes critical to neutrophil function

Front 79

What are the substances within non-specific granules in neutrophils?

Back 79

Lysosomes containing:
- Acid hydrolases
- Lysozyme
- Other enzymes

Front 80

What are the substances within specific granules in neutrophils?

Back 80

- Alkaline phosphatase
- Amino peptidase
- Collagenase
- Other enzymes

Front 81

What are the known functions of neutrophils?

Back 81

- Phagocytosis
- Destruction of microorganisms
- Initiation of inflammatory process

Front 82

Mature Eosinophils:
- Size
- Proportion of WBCs
- Nuclei
- Cytoplasm

Back 82

- 10-14 µm (larger than neutrophils)
- 0-7%
- Bi-lobed nucleus
- Reddish granules w/ darker red or orange cytoplasm

Front 83

What do the specific (secondary) granules of Eosinophils contain?

Back 83

- Major Basic Protein (MBP)
- Other basic proteins that combat parasites

Front 84

What are the functions of Eosinophils?

Back 84

Increased in number in parasitic worm infections and allergic reactions

Front 85

Why do Eosinophils stain red?

Back 85

Large number of arginine residues in major basic protein give granules their eosinophilic staining property

Front 86

Eosinophils function outside the circulation in what tissues? Why are eosinophils in the tissue spaces rather than in blood vessels?

Back 86

- Can be found in the dermis of the skin and in CT components of the respiratory tree, GI tract, uterus, and vagina
- They are within tissue spaces so that they can encounter foreign microorganisms and antigens

Front 87

Mature Basophils:
- Size
- Proportion of WBCs
- Nuclei
- Cytoplasm

Back 87

- 8-10 µm (small)
- <1%
- Obscured irregular nucleus
- Specific granules stain very dark purple and obscure nucleus

Front 88

How might antihistamines affect Basophils?

Back 88

Anti-histamines inhibit degranulation of basophils

Front 89

What kind of granules are found within monocytes and lymphocytes?

Back 89

No specific (secondary) granules but may contain some primary granules

Front 90

Monocytes:
- Size
- Proportion of WBCs
- Nuclei
- Cytoplasm

Back 90

- 15-20 µm (largest WBCs)
- 5-12%
- Large, eccentric, pale staining (bc of euchromatin) and indented to give horseshoe or S shape
- Pale gray-blue cytoplasm and variably vaculated

Front 91

When monocytes enter peripheral tissues they differentiate into what?

Back 91

Macrophages

Front 92

What are the functions of Macrophages / Monocytes?

Back 92

- Phagocytosis
- Antigen presentation on MHC molecules to T cells which are stimulated to respond

Front 93

Lymphocytes:
- Size
- Proportion of WBCs
- Nuclei
- Cytoplasm

Back 93

- 5-15 µm
- 20-50%
- Large, round, dark-staining nucleus that takes up most of volume
- Cytoplasm is thin, blue rim

Front 94

The larger lymphocytes may be activated B cells which secrete what?

Back 94

Antibodies

Front 95

What are these structures? How can you tell?

Back 95

Platelets
- Purple blue particles
- Looks like debris
- Smaller than RBCs, less numerous, and variably shaped

Front 96

Platelets are derived from large cells in BM called what?

Back 96

Megakaryocytes

Front 97

What is the function of platelets?

Back 97

Involved in blood clot formation

Front 98

How many nuclei are present in platelets? How many nuclei are present in megakaryocytes?

Back 98

- Platelets: none
- Megakaryocytes: one

Front 99

What is Thrombocytopenia? Principal symptom?

Back 99

- Condition in which there is an abnormally low number of platelets in peripheral blood
- Mucocutaneous bleeding