Introduction to haematology Flashcards
Plasma constituents
clotting or coagulation factors
albumin
antibodies
Buffy coat constituents
platelets
WBC
3 main functions of blood
transportation
maintain vascular integrity
protect from pathogens
Blood - transport
oxygen and carbon dioxide - RBC
nutrients, waste and messages in plasma
blood - prevent leaks
clotting factors and platelets
blood - prevent blockages
anticoagulants and fibrinolytics
blood - protect from pathogens
phagocytosis - granulocytes/monocytes
antigen recognition and ab formation
Development of a RBC
erythroblast - reticulocyte - erythrocyte
WBC
eosinophil, basophil, neutrophil, monocyte, lymphocyte
Myeloid cells
all blood cells apart from lymphocytes
Mesenchymal stem cells
other cell types eg osteoclasts, liver, skin
Stem cells - totipotent or pluripotent?
totipotent
What regulates the flux of stem cell amplification?
hormones and growth factors
eg erythropoietin, G-CSF, thrombopoietin agonists
Where is bone marrow found in adults in children?
bones - children mainly all, elderly axial skeleton
where is erythropoietin made?
kidney in response to hypoxia
reticulocyte count
measure of red cell production
causes of anaemia - decreased production
haematinics deficiency eg iron, folate, vit B12
congenital eg thalassaemia
causes of anaemia - increased loss
bleeding, haemolysis
How many RBC can be made in a day?
10g/L/day
platelets function
haemostasis and immune
Platelet function regulated by…
thrombopoietin
thrombopoietin
made in liver
regulated by platelet mass feedback
platelet life span
7 days
thrombocytosis
spontaneous clots, myeloid malignancy
thrombocytopenia
marrow failure, immune destruction
function of neutrophils
ingest and destroy pathogens (esp bacteria and fungi)
Neutrophil life span
1-2 days
neutrophil speed of response
few hours
neutrophil differentiation
BLAST –> promyelocyte –> myelocyte –> metamyelocyte –> neutrophil
Production of neutrophils regulated by?
G-CSF
therapeutic use of G-CSF
neutropenia
mobilisation of stem cells
Neutrophilia causes
infection or inflammation eg MI, post op
Neutropenia - decreased production and increased consumption
drugs, marrow failure
sepsis, autoimmune
Functions of monocytes
to ingest and destroy pathogens - esp bacteria and fungi
What are macrophages?
subset of monocytes which migrate to the tissues
Eosinophils
allergy
parasites
Lymphocytes - immunity
adaptive
immunological memory
lymphocytosis
pertussis
glandular fever
lymphopenia
lymphoma
Subtypes of lymphocytes
B cells - make antibodies
NK cells
T cells - helper, cytotoxic
Where do B and T cells mature and where are they produced?
produced in bone marrow - B cells mature here
T cells mature in thymus
Where do lymphocytes differentiate into effector cells?
secondary lymphoid organs - LN or mucosal associated lymphoid tissue
Lymphocyte maturation
gene recombination
alpha and beta chains, junctions
Where do B cells activate?
germinal centre (LN)
+ve/-ve selection in bone marrow
gene rearrangement functional receptor +ve
“self antigens” = -ve
HLA class 1
internal antigens on all nucleated cells
HLA class 2
antigens eaten by professional APC
How do systemic diseases affect the blood?
eg RA
anaemia, Fe deficiency, neutrophilia, immune thrombocytopenia etc…
too much proteins
paraproteins
5 diagnostic tools for haematology
FBC
Clotting times for clotting factors, bleeding time for platelets
chemical assays - iron (ferritin), B12, folate
marrow aspirate and trephine biopsy, LN biopsy
imaging eg x-ray, CT angiogram, CT
3 haematology treatments
replacement - blood, haematinics, coagulation factors
transplantation
drugs eg cytotoxic, monoclonal ab etc
Red and white pulp spleen
red - RBC mature
white - immune function
Pancytopenia
RBC+WBC+platelet deficient
hyposplenism
infection with encapsulated bacteria
red cell change
splenomegaly
infections eg EBV, TB, malaria portal hypertension haematological malignancies haemolytic disorder eg thalassaemia connective tissue disorder eg SLE
