Haematopoeisis

Question 1

Haemopoiesis definition

Answer 1

production of red cells, platelets and white cells

Question 2

erythropoiesis definition

Answer 2

red cell production

Question 3

thrombopoiesis definition

Answer 3

platelet production

Question 4

myelopoiesis/granulopoeisis definition

Answer 4

granulocyte production

Question 5

lymphopoeisis definition

Answer 5

lymphocyte production

Question 6

red cell lifespan

Answer 6

120 days

Question 7

What is most frequent blood cell

Answer 7

red cells

Question 8

neutrophils lifespan

Answer 8

7-8hrs

Question 9

platelets lifespan

Answer 9

7-10days

Question 10

What is a “blast” e.g. erythroblast or myeloblast?

Answer 10

nucleated precursor cell

Question 11

What are megakaryocytes?

Answer 11

platelet precursor cells - they are polypoid because have lots of chromosomes because cells don’t divide

Question 12

What are myelocytes?

Answer 12

nucleated precursor between neutrophils and blasts

Question 13

Stem cells have a property of self-renewal but this is lost in descendants. T/F?

Answer 13

True

Question 14

Stem cells are generally dormant during steady-state haemopoiesis. T/F?

Answer 14

True

Question 15

Myeloid definition (s)

Answer 15

can be marrow,
can be lineage e.g. the non-lymphoid,
can be granulocytes precursors or precursors e.g. myeloid:erythroid ratio

Question 16

When does bone marrow start being main site of haemopoiesis?

Answer 16

week 16

Question 17

Haemopoiesis sites during development?

Answer 17

yolk sac, then liver and maybe a bit of spleen, then bone marrow

Question 18

cellularity decreases with age as what replaces cells in marrow? How is it calculated?

Answer 18

fat replaces cells,

subtract age from 100 to give percentage e.g. 80 year old has 20% cellularity

Question 19

Most appropriate bone marrow biopsy location in adult?

Answer 19

posterior iliac crest or sternum

Question 20

Most appropriate bone marrow biopsy location in child?

Answer 20

tibia

Question 21

Bone marrow compartments include cellular, connective tissue matrix and vascular elements. What are the types of cells? (2)

Answer 21

haemopoietic cells,

and non-haemopoeitic cells e.g. adipocytes, fibroblasts, osteoclasts, and osteoblasts

Question 22

What are venous sinuses in bones?

Answer 22

arterioles drain into them and they open into larger central sinuses

Question 23

What is difference between venous sinuses and capillaries?

Answer 23

sinuses are larger and have discontinuous basement membrane

Question 24

Bone marrow sinusoids have discontinuous membranes why?

Answer 24

so cells and nutrients can pass, epithelial cells have long nucleus

Question 25

sinusoid can be widened how?

Answer 25

contraction of adventitial cells

Question 26

What is difference between red and yellow marrow?

Answer 26

red is haemopoeitically active and yellow is inactive

Question 27

what is myeloid:erythroid ratio represent? Clinical relevance?

Answer 27

relationship of neutrophils and precursors to proportion of nucleated red cell precursors, is reversed in haemolysis as a compensatory response so ratio is reversed

Question 28

Assessment of non-lymphoid haemopoiesis? (3)

Answer 28

blood count, blood film, bone marrow examination

Question 29

Assessing lineage of lymphoid cells is done how?

Answer 29

immunophenotyping - studies antigen expression using antibodies specific to different antigens

Question 30

How do we assess haemopoietic progenitor cells?

Answer 30

immunophenotyping