Haematopoiesis Flashcards
sites of human haematopoiesis - foetus
yolk sac
liver and spleen
bone marrow
sites of human haematopoiesis - infant
all bone marrow
sites of human haematopoiesis - adult
central skeleton
proximal ends of femur
what can a multipotent haematopoietic stem cell (haemocytoblast) differentiate into
haemocytoblat
common myeloid progenitor
common lymphoid progenitor
what can common myeloid progenitor cells differentiate into
megakarocyte
erythrocyte
mast cell
myeloblast
what do megakarocytes differentiate into
thrombocytes
what can myeloblasts differentiate into
basophils
neutrophils
eosinophils
monocytes
what do monocytes differentiate into
macrophages
what can common lymphoid progenitor cells differentiate into
natural killer cells (large granular lymphocytes)
small lymphocytes
what can small lymphocytes differentiate into
T lymphocytes
B lymphocytes
what do B lymphocytes differentiate into
plasma cells
what cell types are found in bone marrow
stromal cells
fibroblasts
adipocytes
macrophages
endothelial cells
osteoblasts and osteoclasts
control of adult haematopoiesis - extrinsic signalling
growth factors
- cell survival/proliferation
- differentiation
- maturation
- activation
adhesion molecules
- interact with ECM
control of adult haematopoiesis - intrinsic signalling
transcription factors
what is erythropoiesis regulated by
renal erythropoietin which is stimulated by tissue oxygen
what is myelopoiesis regulated by
G-CSF - granulocytes
M-CSF - macrophages
IL-5 - eosinophils
what is thrombopoiesis regulated by
thrombopoietin from liver
feedback mechanism controls platelet count
types of white blood cell
neutrophils
lymphocytes
monocytes
eosinophils
basophils
too much (-cytosis)
erythrocytosis
leucocytosis
thrombocytosis
too little (-cytopaenia)
anaemia (red)
leucopenia (white)
thrombocytopenia (platelets)
pancytopenia (all)
anaemia symptoms
lethargy
SOB
chest pain
headache, dizziness
pallor
depend on degree of anaemia, speed and comorbidities
examples of anaemia
blood loss
reduced RBC production
increased RBC destruction
reduced RBC production
deficiency - iron, b12, folate
malignancy
chronic disease, kidney disease
thalassaemia
bone marrow failure
increased RBC destruction
haemolysis, e.g. autoimmune
sickle cell disease
iron deficieny
chronic blood loss - menstruation, GI bleeding
dietary - veggie, vegan, toddlers
malabsorption - coeliac, gastric surgery
increased requirements - pregnancy, growth
megaloblastic anaemia
defective DNA synthesis during RBC production causing cell growth without division
macrocytic anaemia
usually due to b12 or folate deficiency
macrocytic anaemia (increased MCV)
anisocytosis, oval macrocytes
neutropaenia with hyper segmented neutrophils
thrombocytopaenia
reduced reticulocytes
non haematological effects
folate dietary sources
green veg
folate free diet causes deficiency in weeks
folate deficiency
inadequate intake
malabsorption - coeliac
excess consumption - pregnancy
drugs - e.g. anticonvulsants
b12 dietary
meat
dairy
fish
b12 deficiency
vegan diet
autoimmune - pernicious anaemia
malabsorption - gastric/ileal surgery
haemolytic anaemia
excessive/premature RBC breakdown
- spherocytes or fragments
- anaemia and reticulocytosis
- raised bilirubin and LDH
extra or intravascular
many causes - inherited or acquired
polycythaemia/erythrocytosis
increased haematocrit and haemoglobin
absolute increased red cell mass
- primary: polycythaemia rubra vera
- secondary: increased EPO, chronic hypoxia, renal tumours
relative/apparent reduced plasma volume
what are white cells called
leucocytes
types of white cell
monocyte
lymphocyte
neutrophil
eosinophil
basophil
leucocytosis
too many white cells
leucopenia
too little white cells
neutrophilia
infection
inflammation
malignancy
bone marrow infiltration
steroids
pregnancy
g-csf
monocytosis
acute or chronic infection
connective tissue disease
eosinophilia
allergy
parasites
skin diseases
drugs
main type of leucopaenia
neutropenia
reasons for leucopenia
infections
- recurrent bacterial skin
- mouth ulcers
- overwhelming sepsis
- unusual infections
thrombocytosis
too many platelets
primary thrombocytosis
essential thrombocytosis or another myeloproliferative disorder
secondary thrombocytosis
infection/inflammation/surgery
post-splenectomy
iron deficiency
malignancy
thrombocytopaenia
too few platelets
symptoms of thrombocytopaenia
bruising
gum bleeding
nose bleeds
petechiae
prolonged bleeding from cuts
TCP - increased destruction/consumption of platelets
immune - immune thrombocytopenia pupura, drugs (e.g. heparin), autoimmune, infection
non-immune - hyperplenism, MAHA
TCP - decreased production of platelets
bone marrow failure
b12/folate deficiency
drugs/alcohol
infection
liver disease
pancytopenia
severe infection
hypersplenism
megaloblastic anaemia
myelosuppressive drugs
bone marrow failure
