Bone Marrow

Question 0

Detail the phases of hemopoiesis

Answer 0

Mesoblastic phase (2 weeks post conception, Yolk sac)
Hepato-splenic phase (2nd month, Liver and spleen)
Myeloid phase (2nd trimester and throughout life, bone marrow)
Leukocytes appear by 8th week of gestation

Question 1

What are the two types of hemopoietic tissue in bone?

Answer 1

Bone marrow (myeloid tissue)
Lymphoid tissue

Question 2

Where does hematopoeisis occur post-birth?

Answer 2

Red bone marrow in the medullary cavity of long bones when young. That turns to yellow marrow when older. Can be repopulated to red if need be All red bone marrow is usually in the epiphyses (head) of bone

Question 3

What is the stroma of bone marrow?

Answer 3

3D network of reticular ad adventital cells and reticular fibers (type III collagen)

Question 4

Properties of capillaries in the stroma

Answer 4

Sinusoidal formed by continous layer of endothelial cells reinforced by reticular cells and fibers

Question 5

What is the parenchyma of bone marrow?

Answer 5

Divided into hematopoietic compartments and responsible for the synthesis of erythrocytes and leukocytes

Question 6

What are megakaryocytes?

Answer 6

Largest cells in bone marrow. Makes platelets

Question 7

Erythroblastic islets function to?

Answer 7

Make RBC

Question 8

Fibroblasts function to do what in the bone marrow?

Answer 8

Support the endothelium of the sinus capillaries and also produce the reticular fibers

Question 9

T or F: Endothelial cells in bone marrow can be darkly stained by a separate stain to H&E

Answer 9

T

Question 10

What stage of hematopoietic development are morphological differences apparent?

Answer 10

Precursor cells (blasts)

Question 11

Pluripotent stem cells are made into what two possible cells for hematopoietic asymmetric differentiation?

Answer 11

Lymphoid multipotential cells

Myeloid multipotential cells

Question 12

Lymphoid multipotential cells do?

Answer 12

Migrate to lymphoid organs and form LCFC (lymphocyte colony forming cell)progenitor cells then lymphoblasts then B and T lymphocytes

Question 13

What is the process of cell differentiation from pluripotent cells?

Answer 13

Stem cells to progenitor cells to precursor cells (blasts) to mature cells

Question 14

Describe the morphologic and mitotic characteristics of stem cells

Answer 14

Not morphologically distinct, all have aspect of lymphocytes. Low mitotic activity, self renewing, scarce in bone marrow

Question 15

Describe the morphologic and mitotic characteristics of progenitor cells

Answer 15

Not distinguishable, have general aspect of lymphocytes, high mitotic activity, self-renewing, common in marrow and lymphoid organs, mono- or bipotential

Question 16

Describe the morphologic and mitotic characteristics of progenitor cells

Answer 16

Beginning of morphological differentiation, high mitotic activity, not self renewing, common in marrow and lymphoid organs, monopotential

Question 17

Describe the morphologic and mitotic characteristics of mature cells

Answer 17

Clear morphologic differentiation, no mitotic activity, abundant in blood and hematopoietic organs

Question 18

Myeloid multipotential cells (stem cell) can be made into what?

Answer 18

Erythrocyte colony forming cells (ECFC), Megakaryocyte forming cell, MGCFC/Monocyte-colony-forming cell/Granulocyte-colony-forming cell, Eosinophil colony forming cell (EoCFC), and Basophil-colong-forming cell BCFC

Question 19

Trace production of B and T lymphocytes from progenitor cells

Answer 19

Pluripotent to lymphoid multipotential cells (migrate to lymphoid regions) to LCFC to Lymphoblast to B and T lymphocytes

Question 20

Trace production of Erythrocytes

Answer 20

PP cells to Myeloid multipotential cell in bone marrow to ECFC to Erythroblasts to Erythrocytes

Question 21

Trace production of megakaryocytes

Answer 21

PP cell to Myeloid multipotential cell in bone marrow to megakaryocyte forming cell to megakaryoblast to megakaryocyte

Question 22

Trace formation of monocytes

Answer 22

PP cell to Myeloid MP cell in bone marrow to MGCFC to MCFC to promonocyte to monocyte

Question 23

Trace the formation of neutrophilic/eosinophilic/basophilic granulocytes

Answer 23

PP cell to myeloid MP in bone marrow to -CFC (G,Eo,B) to Neutro/Eosino/Basophilic myelocyte to Neutro/Eosino/Basophilic granulocyte

Question 24

Pluripotent cells in bone marrow are how abundant?

Answer 24

Very rare <0.1% of nucleated cells in bone marrow

Question 25

When are growth factors most effective on hematopoetic cells during differentiation?

Answer 25

Between progenitor and precursor cell stage. Growing to that point and decreasing after

Question 26

Follow Erythropoiesis stages

Answer 26

Proerythroblast to basophilic erythroblast to polychromatophilic erythroblast to orthochromatophilic erythroblast to reticulocyte to erythrocyte

Question 27

Follow granulopoiesis for neutrophil

Answer 27

Myeloblast to premyelocyte to Early neutrophilic myelocyte to late neutrophilic myelocyte to neutrophilic metamyelocyte to band cell to mature neutrophil

Question 28

Follow granulopoiesis for eosinophil

Answer 28

Myeloblast to premyelocyte to early eosinophilic myelocyte to late eosinophilic myelocyte to eosinophilic metamyelocyte to mature eosinophil

Question 29

Follow granulopoiesis for basophil

Answer 29

Myeloblast to premyelocyte to early basophilic myelocyte to late basophilic myelocyte to mature basophil

Question 30

A proerythroblast leads to how many RBC after erythropoiesis?

Answer 30

8 cells

Question 31

Properties of proerythroblast

Answer 31

Large, loose lacey chromatin, very visible nuceoli (ribosomes), basophilic cytoplasm

Question 32

Properties of basophilic erytroblasts

Answer 32

Onset of Hb synthesis, strong basophilic cytoplasm, condensed nucleus no nucleoli

Question 33

Onset of Hb synthesis occurs at what stage?

Answer 33

Basophilic erythroblast

Question 34

Properties of polychromatophilic erythroblast

Answer 34

Cytoplasm filled with Hb, polyribosomes begin to decrease, final stage of mitosis possible

Question 35

What is the last stage of mitotic division possibility for RBC?

Answer 35

Polychromatophilic erythroblast

Question 36

Properties of orthochromatophilic erythroblasts

Answer 36

Cytoplasm filled with Hb, few polyribosomes, condensed nucleus, sometimes called a normoblast (late orthochromatophilic erythroblast)

Question 37

Properties of reticulocytes

Answer 37

Anucleate, most immature form released into blood

Question 38

Length of time for RBC production?

Answer 38

3-5 days. Last for 120 days

Question 39

How does precursor RBC lose nucleus?

Answer 39

Via pyknotic body that is eaten by macrophage

Question 40

What is erythropoietin?

Answer 40

cytokine that pushes erythroblast toward RBC differentiation

Question 41

Properties of myeloblast

Answer 41

Large round nucleus with finely dispersed nucleus, visible nucleoli

Question 42

Properties of promyelocyte

Answer 42

Basophilic cytoplas and azurophilic granules (lysosomes)

Question 43

Properties of Myelocyte

Answer 43

Coarse chromatin, neutrophilic,eosinophilic, or basophilic specific granules appear, final stage at which mitosis can occur

Question 44

When do azurophilic granules form?

Answer 44

Promyelocyte phase

Question 45

When do specific granules appear in granulopoiesis?

Answer 45

Myelocyte phase

Question 46

When does mitosis stop in granulopoiesis?

Answer 46

Myelocyte phase

Question 47

Properties of metamyelocyte

Answer 47

Indented nucleus with coarse chromatin. | N,E, or B specific granules increase in number

Question 48

Band form properties

Answer 48

Band or Ribbon shaped nucleus | Most immature stage released to circulating blood

Question 49

Stages of Monopoiesis

Answer 49

Monoblast to Promonocyte to Monocyte

Question 50

Properties of monoblast

Answer 50

Similar to myeloblast (large round nucleus with dispersed chromatin and visible nucleoli)

Question 51

Properties of promonocyte

Answer 51

Large cell, basophilic cytoplasm, slightly indented nucleus with lacy chromatin and evident nucleoli, last mitotic stage

Question 52

Last mitotic stage of monopoiesis

Answer 52

Promonocyte

Question 53

Location of lymphopoiesis

Answer 53

Circulating lymphocytes originate mainly in thymus and peripheral lymphoid tissue but all lymphocyte progenitors initially come from bone marrow.

Question 54

Stages of lymphopoiesis

Answer 54

lymphoblast to prolymphocyte to lymphocyte

Question 55

Properties of lymphoblast

Answer 55

first identifiable progenitor in bone marrow, large cell capable of dividing 2-3 times

Question 56

Properties of prolymphocyte

Answer 56

Smaller than lymphoblast, more condensed chromatin, lack surface antigens (T&B), migrate to lymphoid tissue to undergo further maturation and become immunocompetent

Question 57

Two types of leukemia

Answer 57

Chronic and Acute

Question 58

Properties of chronic leukemia

Answer 58

Slowly progressive, proliferating cells are partly or completely differetiated e.g. myelocytes, metamyelocytes, band cells seen in chronic granulocytic leukemia

Question 59

Properties of acute leukemia

Answer 59

Rapidly progressive, proliferating cells are undifferentiated precurosors e.g. myeloblasts as in acute myeloblastic leukemia

Question 60

Stages of platelet formation

Answer 60

Megakaryoblast to Megakaryocyte to Platelets

Question 61

What is thrombocytopenia?

Answer 61

Severe reduction in number of circulating platelets.

Question 62

What are the two types of thrombocytopenia purpura?

Answer 62

Petichiea (small dark spots of clotting) and Echymoses (bruise)

Question 63

T or F: Leukemia, metastatic cancer, and chemo drugs can lead to thrombocytopeneia

Answer 63

T