Haemopoiesis

Question 1

What is the producion of platelets known as?

Answer 1

thrombopoieisis

Question 2

what is the function of platelets?

Answer 2

primary haemostasis

Question 3

What is the lifespan of RBCs?

Answer 3

120 days

Question 4

Waht is the lifespan of neutrophils?

Answer 4

7-8 hours

Question 5

What is thel ifespan of platelets?

Answer 5

7-10days

Question 6

What is the units for red cells?

Answer 6

x10^12/L

Question 7

What are the units for platelets and neutrophils?

Answer 7

x10^9/L

Question 8

What is a blast?

Answer 8

nucleated precursor cell

Question 9

What is special about megakaryocytes?

Answer 9

polyploid nucleus which can divide without dividing the cyoplasm

Question 10

What is a myelocyte?

Answer 10

nucleated precursor between neutrophils and blasts

Question 11

What condition are there increased numbers of myelocytes?

Answer 11

chronic myeloid leukaemia

Question 12

What happens when a haemopoeitic progenitor cell dvidies?

Answer 12

produces 2 daughter cells, but one of them is identical to parent cell= self-renewal

Question 13

What is self-renewal?

Answer 13

a property of stem cells, lost in descendents

Question 14

During steady-state haemopoiesis what happens to stem cells?

Answer 14

quiescent/dormant

Question 15

What can myeloid mean?

Answer 15

marrow; lineage (non-lymphoid); granulocytes and precurosors

Question 16

What germ layer are haemopoeitic stem cells derived from?

Answer 16

mesoderm

Question 17

What is the first site of erythroid activity in the fetus

Answer 17

yolk sac

Question 18

When does yolk sac haemopoiesis stop

Answer 18

week 10

Question 19

When does liver haemopoeisis begin?

Answer 19

week 6

Question 20

When does splenic haemopoiesis begin?

Answer 20

week 12

Question 21

When does bone marrow haemopoiesis begin?

Answer 21

week 16

Question 22

What bones does haemopoiesis take place in adults?

Answer 22

vertebra; sternum; rib; prox parts of long bones; skull (axial skeleton)

Question 23

What are the two types of bone?

Answer 23

trabecular and cortical

Question 24

What is the interface of bone and bone marrow?

Answer 24

endosteum

Question 25

What non-haemopoetic cells are found within the bone marrow?

Answer 25

adipocytes; fibroblasts; osteoclasts; osteoblasts

Question 26

what is the function of haemopoietic cells within the bone marrow?

Answer 26

produce cytokines to influence haemopoeissi

Question 27

How does bone marrow get its blood supply?

Answer 27

nutrient artery and periosteal network

Question 28

What do arterioles in the bone marrow drain into?

Answer 28

sinuses

Question 29

What is the difference between capillariesand sinsuses?

Answer 29

sinuses are larger and have a diconstinous basement membrane

Question 30

What other organs aside from bone marrow have sinusoids?

Answer 30

liver and spleen

Question 31

What is the function of the fenestrations between endothelial cells in sinuses?

Answer 31

allow produced blood cells in circulation

Question 32

What is release of red cells associated with?

Answer 32

sinusoidal dilatation; increased blood flow

Question 33

How do neutrophils reach the sinusoid?

Answer 33

activtrly migrate by chemotaxis

Question 34

What is the relationship between megakaryocytes and sinusoids?

Answer 34

extend long branching processes called proplatelets into vessels

Question 35

What is the difference between red and yellow bone marrow?

Answer 35

red is haemopoieticall active whereas yellow marrow is fatty and inactive

Question 36

How is % marrow cellularity calculated?

Answer 36

100-age = cellularity %

Question 37

What is the normal myeloid:erythroid ratio?

Answer 37

myeloid precursors are higher due to shorter lifespan than red cell precursors

Question 38

When may the myeloid:erythroid ratio change?

Answer 38

during haemolysis

Question 39

How is haemopoiesis regulated?

Answer 39

intrinsic properties of cells eg transcription factors unique to certain cells; signals from microenvironment can influence intrinsic cell properties

Question 40

Why does erythroid maturation occur around nurse macrophage islands?

Answer 40

macrophage provides growth factors nutrients for development

Question 41

What is the neutrophil and its maturation regulated by?

Answer 41

granulocyte-colony stimulating factor

Question 42

What hormone regulates megakaryocytes?

Answer 42

thrombopoietin

Question 43

What is name for the anatomical site which haemopoietic stem cells occupy?

Answer 43

niche

Question 44

What is the function of the niche?

Answer 44

provides signal for expansion; differention or dormancy aroudn vasculature- different cytokines

Question 45

How can precursor cells be investigated?

Answer 45

bonw marrow aspirate or biospy

Question 46

How is haemopoeisis of morphologically indistinguishable cells assessed?

Answer 46

immunophenotyping and cytochemistry

Question 47

What is immunophenotyping?

Answer 47

identifying patterns of antigen expression unique to a cell lineage using antibodies specific to different antigens