white cell haemaopoiesis

Question 1

what are the three main types of white cells

Answer 1

granulocytes
monocytes
lymphocytes

Question 2

what are the three main types of granulocytes

Answer 2

neutrophils
eosinophils
basophils

Question 3

what are the three main types of lymphocytes

Answer 3

B cells
T cells
NK cells

Question 4

what are the natural lifespans of RBCs, neutrophils and platelets

Answer 4

RBCs: 120 days

neutrophils: 7-8 hours
platelets: 7-10 days

Question 5

which cell count will be affected first if there are problems with haematopoiesis

Answer 5

neutrophils

Question 6

what are blast cells

Answer 6

nucleated precursor cells

eg erythroblast

Question 7

what is a megokaryocyte

Answer 7

platelet precursor with a polyploid nucleus

Question 8

what is a reticulocyte

Answer 8

immediate red cell precursor

Question 9

what is a myelocyte

Answer 9

nucleated precursor between neutrophil and blast

Question 10

what type of cell do precursor cells arise from

Answer 10

haemopoietic progenitor cells

Question 11

what type of cell do haemopoietic progenitor cells arise from

Answer 11

haemopoietic stem cells

Question 12

how is a stem cell different from a progenitor cell

Answer 12

it is able to self renew

Question 13

do cells divide more or less as they become more differentiated

Answer 13

more

Question 14

what are the three possible meanings of myeloid

Answer 14

bone marrow
non-lymphoid cells
granulocytes and precursors

Question 15

where are the main sites of haemopoiesis in adults

Answer 15

axial skeleton, pelvis, proximal long bones

Question 16

how is blood supplied to the bone marrow

Answer 16

via the nutrient artery and from periosteal arteries

Question 17

how does the vasculature of the bone marrow differ from normal vascular structure

Answer 17

the arterioles do not lead into capillaries, but into sinuses

Question 18

how do sinuses differ from capillaries

Answer 18

discontinuous basement membrane

larger

Question 19

what is fenestration

Answer 19

openings between endothelial cells in sinuses

Question 20

what is the function of adventitial cells in sinuses

Answer 20

contain smooth muscle filaments which contract to open up the sinus

Question 21

what are proplatelets

Answer 21

long branding processes that megakaryocytes extend into sinusoidal vessels, which then break off and mature to become platelets

Question 22

what is the difference between red and yellow bone marrow

Answer 22

red marrow is haemopoietically active

yellow marrow is inactive and mostly replaced by fat

Question 23

what is the myeloid:erythroid ratio

Answer 23

relationship of neutrophils and precursors to proportion of nucleated red cell precursors

Question 24

the myeloid:erythroid ratio is normally in favour of…

Answer 24

neutrophils

Question 25

in what scenarios might the myeloid:erythroid ratio be reversed

Answer 25

anaemia
haemolysis
increased RBC production

Question 26

how is haemopoiesis regulated

Answer 26

intrinsic properties of cells
signals from immediate surroundings
specific anatomical areas (niches) for optimal developmental signals

Question 27

describe a haemopoietic cell’s niche

Answer 27

near vasculature (arteriole or sinusoid)
provides access to different signals

Question 28

how can haemopoiesis be assessed

Answer 28

FBC
cell indices
morphology
bone marrow examination

Question 29

how are lymphoid cells identified

Answer 29

immunophenotyping