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Flashcards in Hemopoiesis Deck (74):
1

% of body weight blood and bone marrow make

Bone marrow-5 percent
Blood- 10 percent

2

When does hemopoiesis begin?

1-2 weeks post-conception

3

What is the primary site of postnatal hemopoiesis

Bone marrow

4

Hemopoiesis

Formation of blood cells

5

Myelopoiess

Production of marrow or blood cells derived from marrow

6

Leukopoiesis

Production of white blood cells

7

Erythropoiesis

Production of erythrocytes

8

Lymphopoiesis

Production of lymphocytes

9

Granulopoiesis

Production of granulocytes

10

Extramedullary myelopoiesis

Production of myeloid elements at sites other than bone marrow

11

Hemopoiesis location 1-2 weeks post-conception

Embryological site= Mesoderm of yolk sac (blood islands)

12

Hemopoiesis location 6 weeks of gestation to birth

First trimester=liver

13

Hemopoiesis location during second trimester to birth

Spleen

14

Hemopoiesis location third trimester of gestation throughout postnatal life

Bone marrow

15

What hemopoietic areas can be reactivated if needed as postnatal site of hemopoiess (extramedullary)

Liver and Spleen

16

What type of bone marrow is in fetus?
-Indicates

Red marrow
-active myelopoiess

17

What type of bone marrow is in adults?

Red marrow (flat bones, vertebrae, long bone epiphyses)
-Active myelopoiesis

Yellow marrow
-Inactive myelopoiesis

18

Yellow marrow
-made of
-types of cells

Adipose CT

Adipocytes occupy space not needed for hemopoetic cells

19

T/F Yellow marrow can not be re-activated

F

It can be re-activated

20

How do WBC get into circulation

Central vein

21

Sinus of bone marrow is lined by

Endothelial cells

22

Stroma of bone marrow (2)

Reticular CT forms open lattice

Adventitial reticular cells (type of reticular cell)

23

Adventitial reticular cell fxn (5)

1-Produce and surround reticular fibers (type III collagen)
2-Prevent exposure to platelets (prevents clotting)
3-Branching of cytoplasmic processes forms scaffold for hemopoietic cells
4-Provide structural support for sinusoids
5-Differentiate into adipocytes

24

Bone marrow structure- sinusoids
-Structure
-Connect

-Wide, anastomotic vascular channels

-Connect branches from central artery to central vein

25

T/F Central artery is larger that the central vein

T

26

What is the benefit of the central artery being larger than the central vein?

Increases pressure in the sinusoids to prevent their collapse as cells are produced in hemopoietic tissue

27

Sinusoids endoethelial lining is supported by

Reticular CT and adventitial reticular cells

28

Where are MQ located in relation to sinusoids

Along outer wall of sinusoids and among hemopoietic cell groups

29

Fxn of MQ (3)

1-Eliminate old RBC, malformed cells, extruded nuclei from maturing RBC

2-Regulate differentiation of hemopoietic cells

3-Deliver Fe to developing RBC for heme formation

30

Pluripotential hemopoietic stem cell
-primary cell of
-What % of nucleated cells in BM
-A part of what population

-Primary cell of origin (undifferentiated) for all blood cells

-0.1 percent

-Null cell population of peripheral blood....morphogically indistinguishable from small lymphocyte

31

Multipotential hemopoietic stem cells
-AKA
-Subpopulations

-CFUs (colony forming units): group of cells with a common purpose and form specific different subpopulations of cells

-Lymphocytes (CFU-Ly)
-Myeloid cells=all other blood cells (CFU-GEMM or CFU-S)

32

GEMM

Granulocyte
Erythrocyte
Monocyte
Megakaryocyte

33

What is an indicator of poietic stem cell?

CD34+ Ag

34

Progenitor cells
-AKA
-Fxn

Committed CFU cells or Unipotential CFU

Can form only one or two specific type of blood cells

35

Precursor cells
-AKA
-Fxn

AKA maturing cells

Differentiates into mature cell

36

T/F Some stages of development in precursor cells may be found in peripheral blood

T

37

Regulation of hemopoiesis (2)

Indirect control

Direct control

38

Indirect control of hemopoiesis

Via physiological demands to maintain homeostasis of the body

39

Direct control of hemopoiesis

Via growth factors and cytokines

40

What are pluropotential and multipotential stem cells influenced by?
-Type of control
-growth factors
-Cytokines

Direct control

-Steel factor or stem cell factor (SCF) in CM of stromal cells
-Granulocyte-MQ colony stimulating factor (GM_CSF)
-IL-1,3,6

41

Unpotential progenitor cells influenced by
-Control
-Growth factors

Direct control

Stem cell factor
Erythropoietin
Thrombopoietin
GM-CSF
G-CSF
M-CSF

42

Most important growth factors and IL?

GM-CSF
G-CSF
M-CSF
IL-1,3 6
Erythropoietin
Thrombopoietin

43

Where did a lot of the important GF and IL originate?

MQ/monocyte

44

Hemopoietic cells are capable of (3)

Erythropoiesis (make RBC)
Leukopoiesis (make WBC)
Thrombopoiesis (make platelets)

45

Production of erythrocytes stimulated by

Erythropoietin from kidney

46

Erythropoietin acts on

CFU-GEMM cells to become BFU-E cells (burst forming unit)

47

RBC formation is coordinated to meet
(2)

Metabolic needs of the body
-O2 transport requirements
-Replacement of worn out RBCs

48

What are the general cellular changes during sequential differentiation and maturation?

-Progressive decrease in size of cell and nucleus
-Gradual condensation of nuclear chromatin and heterochromatin formation
-Polyribosome increase then progressive decrease
-Progressive hemoglobin synthesis
-Gradual loss of organelles

49

Give maturation stages (earliest-->most mature) of erythrocyte

Pluripotent stem cell
Myeloid stem cell
BFU-E
CFU-E
Rubriblast
Prorubricyte
Rubricyte
Metarubricyte
Reticulocyte
Erythrocyte

50

Rubriblast
AKA
Formed from

Proerythroblast, pronormoblast

CFU-E

51

Rubriblast phenotype
Polyribosomes
Nucleuolus
Golgi
Transcription

Numerous polyribosomes
Nucleolus present
(-) Golgi image may be observed
Transcription of chromatin and mitosis

52

What gives rubriblast basophilic stain?

Polyribosomes

53

Prorubicyte
AKA
Formed from

basophilic erythoblast, basophilic normoblast

Rubriblast

54

Prorubicyte phenotype
Nucleus
Chromatin
Polyribosomes
Hemoglobin
Transcription

Smaller cell and nucleus from rubriblast
Chromatin begins to condense
ABUNDANT polyribosomes (same number in more condensed area)
Hemoglobin synthesis begins but is not apparent
Transcrption of chromatin and mitosis

55

Rubricyte
AKA
Formed from

Polychromatic erythroblast, polychromatic normoblast
Prorubicyte

56

Rubricyte phenotype

Transcription

Cell and nucleus smaller than prorubricyte
Condensation of chromatin but light areas are visible in condensed chromatin
Lots of polyribosomes
Hemoglobin synthesis apparent=gray cytoplasm

CLOCK FACED NUCLEUS

Transcription of chromatin and mitosis

57

What stage in erythropoiesis shows apparent hemoglobin synthesis

Rubricyte
-Basophilia of ribosomes plus acidophilia of hemoglobin equal gray color of cytoplasm

58

Metarubricyte
AKA
Derived from

Orthochromatic erythroblast, orthochromatic normoblast

Rubricyte

59

Metarubricyte phenotype
-Nucleus
-Chromatin
-Polyribosomes
-Hemoglobin
-Mitosis

Small cell with PYKNOTIC NUCLEUS
Highly condensed chromatin
Small amount of polyribsosomes
Abundant hemoglobin (pinkish gray cytoplasm)

Mitosis can occur at any stage

60

Reticulocyte
phenotype
Nucleus
Mitosis
polyribosomes
hemoglobin

No nucleus- extruded from metarubricyte
No mitosis
Few polyribosomes (slight gray tint to cytoplasm
Abundant hemoglobin

61

What stage of erythropoiesis can be 1% of peripheral blood in normal small animals

Reticulocyte

62

Reticulocyte derived from

Metaubricyte

63

Last stage of erythropoiesis

Erythrocyte

64

Erythrocyte morphology
size
organelles
Nucleus

Size and shape is variable among species
No organelles
Howell-Jolly bodies may be present (remnant of nucleus (DNA)

65

T/F Granulopoiesis originates from the same multipotential CFU as erythrocytes

T

66

T/F Progenitor cells (unipotential CFU) and early precursor cells are the same for all granulocytes

F

There are specific progenitor cells for each granulocyte

67

What controls what progenitor cell will become a specific granulocyte

Cytokines

68

What is the general trend of granulopoiesis

Decrease in cell size
Irregular nuclear shape with gradual lobation of nucleus
Synthesis of azurophilic granules
Synthesis of specific granules

69

What are the stages of granulopoiesis

Pluripotent stem cell
Myeloid stem cell (CFU-GEMM)
Myeloblast
Promyelocyte
Myelocyte
Metamyelocyte
Stab cell
Granulocyte

70

Myeloblast
Originates from
Granules
Mitosis

Specific progenitor cell (unipotential CFU)

Cytoplasmic granules not visible

Yes to mitosis

71

Promyelocyte
Originates from
Granules
Mitosis

Myeloblast

Primary or azurophilic granules (lyososomes) present and visible in cytoplasm

Yes to mitosis

72

Metamyelocyte
Originates from
Granules
Mitosis
Nucleus

Promyelocyte

Specific granules more prominent than primary granules for granulocytes

No mitosis

Nucleus is eccentric located and less than 50 percent of invagination

73

Band cell
Originates from
Granules
Mitosis
Nucleus
Peripheral blood

Metamyelocyte

Specific granules more prominent than primary granules for each type of granulocyte

No mitosis

Nucleus is eccentric located and MORE THAN 50 percent invagination "ribbon-like"

Can see in peripheral blood

74

Mature granulocyte
Derived from
Granules
Nucleus
Mitosis

Band cell

Prominent specific granules

Nucleus is multilobated and condensed chromatin

No mitosis