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Flashcards in Hematopoiesis Deck (39):
1

Romanovsky Type Blood Stains (basic)

methylene blue - stains RNA-rich cytoplasm heavenly blue (esp if ribosomes)
azure B - stains DNA/GAG-rich nuclei or cytoplasmic granules of basophils/lysosomes crimson

2

Romanovsky Type Blood Stains (acidic)

eosin - general stain for PRO (red-pink)
-Hb of RBC and granules of eosinophils

3

hematopoetic organs

bone marrow (RBC, granulocytes, monocytes)
lymphoid organs (lymphocytes)
fetal (liver)

4

monophyletic theory of hematopoiesis

all blood cells are derived from common pluripotential (hematopoietic) stem cell

5

stages of granulopoiesis

development of granulocytes (neutrophils, eosinophils, basopihls)
myeloblast--> promyelocyte--> myelocyte--> metamyelocyte--> band cell--> mature cell
-first 4 only in bone marrow, last 2 in normal peripheral blood

6

polyphyletic theory

each type of blood cell arises from own stem cell (not widely held theory)

7

blast cell appearance

all blood cells start out like this (RBC, WBC, platelet)
-large cell, 10-15 microns
-large euchromatic nucleus
-several nucleili
-high nucleocytoplasmic ratio
-numerous ribosomes (creates methylene blue stain)
-no cytoplasmic granules

8

what changes a blast must undergo to become a neutrophil

-condense nuclear chromatin (disappearance of nucleoli)
-lobulate nucleus
-appearance of cytoplasmic granules (primary/secondary)
-decrease in cytoplasmic basophilia

9

neutrophil promyelocyte

2nd step after blast; capable of mitosis
-same size as blast
-spherical nucleus with slight chromatin condensation
-nucleoli observed
-growing appearance of primary (azurophilic) granules and primary lysozomes (w/ hydrolytic enzymes

10

neutrophil myelocyte

3rd step, after promyelocyte; losing ability to make DNA/RNA
-nucleus is round/oval and more heterochromatic (azure B); more condensed, less basophilic
-appearance of secondary (specific) granules w/ lysozyme/lactoferrin (kill bacteria)
--cause cytoplasmic color change from heavenly blue to salmon pink

11

neutrophil metamyelocyte

4th step, after myelocyte; no longer able to make DNA/RNA, or mitosis
-kidney-shaped nucleus (beginning of lobulation), more condensed
-no basophilic cytoplasm, and higher ratio of small specific : large azurophilic granules
-salmon-pink cytoplasm

12

neutrophil band cell

5th step, after metamyelocyte; when indentation exceeds 1/2 diameter of nucleus (looks like C or S)
-chromatin condensed, and cytoplasm looks mature
-found in peripheral blood (1-5% total leukocytes)

13

clinical use of % of neutrophil band cells

provides rough indication of rate of neutrophil production in patient
-"shift to the left" - increase in % of bands in buffy coat indicates stress ins placed on bone marrow to create more neutrophils

14

definitive marker of band to mature neutrophil

when segments between lobes have become thin heterochromatic filaments, and nuclei completely lobed

15

kinetics of neutrophil (and other granulocyte) production

9-14 days (blast to mature), mostly in bone marrow
1 day in peripheral blood (circulating and marginating, exchanging between them)
5 days in surrounding tissue (diapedesis)
total life span = 15-20 days

16

differences in eosinophilic development

specific granules are are larger, almost black when first appear
-become pink-red as maturation continues

17

differences in basophilic development

specific granules are much bigger, stain purple in smears

18

distribution of granulocytes

marrow granulocytic reserve (MGR) - cells in bone marrow
total granulocytes in peripheral circulation (TBGP) - granulocytes in peripheral circulation
MCR is 10X TBGP

19

sites of hematopoiesis

flat bones of body
-sternum
-vertebrae
-ribs
-clavicles
-pelvis
-skull

20

components of red blood marrow

small blood vessels
discontinuous sinusoids
hematopoietic cords
hematopoietic stem cell niche
stem cells for other tissues, so can make unrejected cells

21

hematopoetic stem cell niche (in RBM)

interactive structural unit that nurtures stem cells and facilitates their activity (critical for development)
-localized supporting cells, ECM PRO, soluble factors (showing stem cells not randomly distributed)
-found in association with spongy bone (OC/OB, etc.)
-alterations may cause myeloproliferative disease (preleukemic condition)

22

what blasts have to do to become RBCs

decrease cell volume
disappearance of nucleoli/nucleus
increase heterochromatin
decrease cytoplasmic basophilia, increase eosinophilia (hemoglobin)

23

stages of erythropoiesis

blast--> basophilic erythroblast--> polychromatophilic erythroblast--> normoblast--> reticulocyte--> orthochromatic erythroblast--> RBC

24

basophilic erythroblast (BEB)

2nd stage, after blast
-cell/nucleus smaller than blast
-checkerboard chromatin nucleus, loss of nucleolus
-basophilic cytoplasm (b/c increase free ribosomes for globin production)
-lasts 1-2 days, divides 1-2 times

25

polychromatic erythroblast (PCE)

3rd stage, after BEB
-cell/nucleus smaller than BEB
-further chromatin condensation
-gradual shift from intense basophilia to intense acidophilia (b/c increase hemoglobin and decrease ribosome) so double-staining
-lasts 3 days, divides 3-4 times

26

normoblast (NB)

4th stage, after PCE (no more mitosis; terminal)
-cell/nucleus smaller than PCE
-totally heterochromatic
-cytoplasm mostly pink, slight blue

27

fates of normoblasts

80%: extrude nucleus, retain ribosomes --> reticulocyte
20%: lose residual RNA before nuclear extrusion --> orthochromatic erythroblast

28

orthochromatic erythroblast

same color as RBC, just nucleated
-small heterochromatic nucleus, bright eosinophilic cytoplasm
-not present in normal peripheral blood (nucleus pops out before circulation)

29

maturation time for RBCs

1-2 days: BEB
3 days: PCE
3 days: NB --> reticulocyte transition
1 day: reticulocyte --> RBC transition
total 8-9 days

30

erythropoietin

glycoPRO hormone
-made in kidney (via endothelial cells)
-increases rate of mitosis (in blasts, BEB, PCE)
-increases RNA synthesis in developing RBCs (for Hb)
-lessens degree of brain damage after stroke, and stimulated by hypoxia

31

reticular cells

large cells with cytoplasmic processes (mainly phagocytosis of extruded nuclei)
-lots of ingested material in cytoplasm
-large, pale staining nucleus
-plays trophic role in RBC maturation

32

erythroblastic island

developing RBCs that cluster around reticular cells in bone marrow, so that they can phagocytose nuclei

33

plasma cells

basophilic cytoplasm
negative image of Golgi
eccentically placed nucleus
"clock face" chromatin

34

megakaryoblast

large cell 40-50 um diameter
large/spherical nucleus b/c polyploid
homogenous basophilic cytoplasm

35

megakaryocyte

even larger cell (up to 150 um diameter)
lobulated nucleus
increases poidy to 32-64 n (endomitosis)
eosinophilic cytoplasm, w/ azurophilic granules
invaginations of plasma membrane throughout cytoplasm
-forms demarcation channels
-results in partitioning of cytoplasmic fragments to form platelets
-platelets enter discontinuous sinusoids in bone marrow

36

proplatelet model of platelet production

1. extension of psuedopods
2. formation of long extensions (proplatelets)
3. platelets released from ends of proplatelets
4. demarcation channels are membrane reservoir

37

kinetics of platelet formation

4-5 days: megakaryocyte maturation
10 days: platelets circulate
destroyed in spleen/liver, with functional mRNAs (may mitosis?)

38

what blasts must do to become lymphocytes

decrease cell size
condense chromatin
disappear nuclei
acquire cell surface receptors
migrate to thymus (T) or stay in bone marrow (B) for differentiation

39

kinetics of monocyte differentiation

2-3 days: formation in bone marrow
1-2 days: circulation
1-3 months: in tissue as macrophages