Hematpoiesis Flashcards Preview

Hematology > Hematpoiesis > Flashcards

Flashcards in Hematpoiesis Deck (70):
1

What is the usual value for hematocrit?

50%

2

What is the MOA of stroke and MI using rhEPO?

increased blood viscosity
Rapid clotting

3

What is the lifespain of lymphocytes, geerally?

years

4

What is the lifespan of RBCs, generally?

120 days

5

What is the lifespan of platelets, generally?

7-10 days

6

What is the lifespan of granulocytes, generally?

6-8 hours

7

What are the three granulocytes?

Eosiniphils
Basophils
Neutrophils

8

What is the most numerous type of blood cell in the bone marrow?

granulocytes

9

What type of cells in the bone marrow give rise to all other cell types?

stem cells

10

Can you identify stem cells in the bone marrow morphologically?

no

11

What percent of bone marrow is made up of stem cells?

0.1-0.01%

12

What are the cells that provide a microenvironment in bone marrow, for the development of other cells?

Stromal cells (adipocytes, fibroblasts, reticuloendothelial cells)

13

True or false: immature stem cells are only loosely associated with the stromal cells found in the bone marrow

False--very tightly bound

14

What happens to the amount of binding of stem cells to the stromal cells as they mature in the bone marrow?

Weaker binding

15

What regulates the binding of cells in the bone marrow?

Different expression of cell adhesion molecules

16

How do cells in the bone marrow know what to become?

Cytokines inform what they should become

17

What is the cytokine that tells cells in the bone marrow to differentiate into RBCs?

erythropoietin

18

What are the cells that release erythropoietin?

Peritubular cells in the kidney

19

What is the cytokine that is released to stimulate cells to differentiate into neutrophils?

G-CSF

20

What do cells exposed to G-CSF turn into?

Granulocytes (usually PMNs)

21

What are the cells that release G-CSF to increase the production of PMNs?

macrophages at inflammatory sites

22

What inhibits the production of EPO?

Oxygen pressure

23

What doe TGF-beta do to the production of stem cells?

Downregulate

24

What is the trigger to produce EPO?

Hypoxia in the peritubular interstitial cells of the kidney

25

How does TGF-beta decrease the production of cells?

Downregulate the differentiation cytokines

26

What is the chemical that is used to increase the production of bone marrow, and also release the bone marrow cells into the blood?

G-CSF

27

What is the chemical given to chemo pts undergoing radiotherapy, to increase the production of bone marrow?

G-CSF

28

What is the function of GM-CSF?

increases myeloid cell receovery in bone marrow transplantation pts

29

Why isn't MG -CSF used more often to retrieve bone marrow cells?

Causes thrombosis and leay capillary syndrome

30

Which is typically active: yellow or red bone marrow?

Red marrow

31

What is yellow bone marrow?

inactive bone marrow in adipose tissue

32

True or false: in the first few years of life, most of the bone marrow is yellow

False--most is red

33

What is extramedullary hematpoiesis?

hematpoiesis that takes place outside the bone marrow (liver and spleen)

34

What happens to the cell size as they mature?

decrease

35

What happens to the nuclear:cytoplamic ratio as cells mature in the bone marrow?

Decrease

36

What happens to the nucleoi number as a cell matures

Decrease

37

What happens to cytoplasmic staining as a cell matures? What does this indicate?

Darker blue to lighter blue, which indicates less RNA

38

What are retriculocytes?

Immature RBCs

39

When/where in development does erythropoiesis begin to take place? Where next?

embryonic yolk sac
Extramedullary organs

40

What is the normal amount of reticulocytes in the blood?

1%

41

What are band cells?

Immature granulocytes

42

What is the normal percentage of band cells?

3-5%

43

What do band cell look like histologically?

horseshoe shaped nucleus

44

Left shift = ?

More bands

45

Where are granulocytes removed from the blood? What are the cells that remove them?

Phagocytes in the spleen

46

Where are PMNs found in the blood?

Half circulating
Half attached to cell walls

47

What are monocytes?

Baby macrophages

48

What are histocytes?

macrophages in loose CT

49

What are kupffer cells?

Macrophages in the liver

50

What are osteoclasts?

Macrophage in bone that resorb bone

51

What are microglial cells?

macrophages in the CNS

52

What is lymphopoiesis?

production of lymphocytes (T cells/B cells, NK cells)

53

Are NK cells part of adaptive/acquired immunity?

no--innate

54

Where are B cells produced from?

Bone marrow

55

B cells initially only express what antibody on their cell surface?

IgM

56

What happens to immature B cells that only have IgM, that encounter antigen

Undergo apoptosis

57

What are the two outcomes of a B cell encoutering an antigen?

Become plasma cell
Become memory cell

58

Where are T cells produed from? Where do they mature?

Bone marrow
Thymus

59

Once T cells reach the thymus, what are they then called?

thymocytes

60

Where do mature T cells after exiting the thymus?

lymphatic tissue

61

What are the cells that produce thrombocytes?

Megakaryocytes

62

What is the process the megakaryocytes undergo

Endomitosis (nuclear mitosis without cytoplasmic divisions)

63

What cytokine stimulates thrombopoiesis and endomitosis?

Thrombopoietin

64

What happens to old platelets?

Spleen/liver phagocytes eat 'em up

65

True or false: we have an emergency reserve of platelets in the spleen

True

66

What does the absolute cell count provide?

Quantity of each cell type per unit volume

67

What does the differential count provide?

Relative count (% of each cell type)

68

Elevated eosinophils = ?

Allergies or parasitic infection

69

About what percent of WBCs are PMNs, (normally)?

50%

70

What is the normal reticulocyte count (% of RBCs)?

0.5-1.5% of RBCs