white cell haemaopoiesis Flashcards
what are the three main types of white cells
granulocytes
monocytes
lymphocytes
what are the three main types of granulocytes
neutrophils
eosinophils
basophils
what are the three main types of lymphocytes
B cells
T cells
NK cells
what are the natural lifespans of RBCs, neutrophils and platelets
RBCs: 120 days
neutrophils: 7-8 hours
platelets: 7-10 days
which cell count will be affected first if there are problems with haematopoiesis
neutrophils
what are blast cells
nucleated precursor cells
eg erythroblast
what is a megokaryocyte
platelet precursor with a polyploid nucleus
what is a reticulocyte
immediate red cell precursor
what is a myelocyte
nucleated precursor between neutrophil and blast
what type of cell do precursor cells arise from
haemopoietic progenitor cells
what type of cell do haemopoietic progenitor cells arise from
haemopoietic stem cells
how is a stem cell different from a progenitor cell
it is able to self renew
do cells divide more or less as they become more differentiated
more
what are the three possible meanings of myeloid
bone marrow
non-lymphoid cells
granulocytes and precursors
where are the main sites of haemopoiesis in adults
axial skeleton, pelvis, proximal long bones
how is blood supplied to the bone marrow
via the nutrient artery and from periosteal arteries
how does the vasculature of the bone marrow differ from normal vascular structure
the arterioles do not lead into capillaries, but into sinuses
how do sinuses differ from capillaries
discontinuous basement membrane
larger
what is fenestration
openings between endothelial cells in sinuses
what is the function of adventitial cells in sinuses
contain smooth muscle filaments which contract to open up the sinus
what are proplatelets
long branding processes that megakaryocytes extend into sinusoidal vessels, which then break off and mature to become platelets
what is the difference between red and yellow bone marrow
red marrow is haemopoietically active
yellow marrow is inactive and mostly replaced by fat
what is the myeloid:erythroid ratio
relationship of neutrophils and precursors to proportion of nucleated red cell precursors
the myeloid:erythroid ratio is normally in favour of…
neutrophils
in what scenarios might the myeloid:erythroid ratio be reversed
anaemia
haemolysis
increased RBC production
how is haemopoiesis regulated
intrinsic properties of cells
signals from immediate surroundings
specific anatomical areas (niches) for optimal developmental signals
describe a haemopoietic cell’s niche
near vasculature (arteriole or sinusoid) provides access to different signals
how can haemopoiesis be assessed
FBC
cell indices
morphology
bone marrow examination
how are lymphoid cells identified
immunophenotyping
