Intro to Haematology Flashcards
What are the components of blood?
Plasma
Buffy Coat
Red blood cells
What are the contents of blood plasma?
Coagulation factor
Albumin
Antibodies
What are the contents of Buffy coat?
Platelets
White cells
What substances are transported in plasma?
Nutrients
Wastes
Messages
What are the functions of blood?
Transport
Maintaining vascular integrity
Protect from pathogens
How is vascular integrity maintained by the blood?
Prevent leaks - platelets, clotting factors
Prevent blockages - anticoagulants and fibrinolytics
What cells are involved in phagocytosis?
Granulocytes/monocytes
What is the role of lymphocytes?
Antigen recognition
Antibody formation
What are myeloid cells?
RBC
Platelets
Neutrophils, monocytes, basophils, eosinophils
What mediates stem cell specialisation?
Hormones
Growth factors
What is the erythroid differentiation pathway?
Erythroblast
Reticulocyte
Erythrocyte
What is the hormone involved in RBC formation?
Erythropoietin
in response to hypoxia
What is a reticulocyte count?
Measure of RBC production
What are the causes of anaemia?
Decreased production: - Deficient in iron, folate, B12 - Thalassaemias Increased loss: Bleeding, haemolysis
What are Schistocytes?
Fragmented RBC seen in Haemolytic uraemic syndrome
When are microcytic RBC seen?
Iron deficiency
When are macrocytic RBC seen?
Megaloblastic - Folate, B12 deficiency
Non-megaloblastic - Marrow infiltration, drugs
Platelet production is regulated by what?
Thrombopoeitin (Liver)
platelet mass feedback
What is the lifespan of a platelet?
7 days
What are the causes of Thrombocytopenia?
Marrow failure
Immune distruction
What is the function of neutrophils?
Ingest pathogens (Bact/fungi ++) Regulated by macrophages, IL-17
What is the lifespan of a neutrophil?
1-2 days
What is the sequence of Neutrophil differentiation?
Blast Promyelocyte Myelocyte Metamyelocyte Neutrophil
What are the causes of Neutrophilia?
Production stimulated by G-CSF
Infection
Inflammation
What are the causes of Neutropenia?
Decreased production (Drugs, marrow failure) Increased consumption (Sepsis, autoimmune)
What is the function of monocytes?
Ingest pathogens (Bacteria/fungi++) Migrate into tissues and become macrophages
What is the role of Eosinophils?
Parasites and allergies
What are the causes of Lymphocytosis?
Infectious mononucleosis
Pertussis
What are the causes of Lymphopenia?
Post-viral state
Lymphoma
What are the subtypes of Lymphocytes and what are their functions?
B cells - make antibodies
T cells - helper, cytotoxic, regulatory
NK cells - Perforin & Granzyme
Where are lymphocytes made?
B cells mature in bone marrow
T cells in thymus
What is positive and negative selection?
Positive selection - gene rearragement results in functional receptor cell
Negative selection - cell recognises ‘self’ antigens and is triggered to die
B cells Surviving this pass to periphery
What are the 2 classes of Human Leucocyte antigen?
Class I: Display internal antigens on all nucleated cells
Class II: display antigens eaten by antigen presenting cells
What does HLA differentiate?
Self vs. non self
Uninfected vs. Infected
What are the haematological diagnostic tools?
FBC Clotting times (platelet and leucocyte function) Chemical assays (Iron, B12, Folate) Marrow aspirate Lymph node biopsy
What are the Haematology replacement therapies?
Blood
Haematinics
Coagulation factors
Plasma exchange
What substances stimulate neutrophil production?
Interleukins
Granulocyte-colony stimulating factor (G-CSF)
What is the ‘first’ B cell?
Progenitor B cell
What is the sequence of B-cell maturation in bone marrow?
Progenitor B cell –>
Pre B cell –>
Immature B cell –> (out) –> Lymph cells
Most lymphomas arise from what?
Somatic hypermutation (specialising of B cells)
What blood condition is associated with rheumatoid arthritis?
Anaemia (Fe deficiency)
Neutrophilia
Folate deficiency is associated with what medication?
Methotrexate
What is normal haemoglobin?
Male: 135-170 g/L
Female: 120-160 g/L
What is normal platelet count?
150-400
What is normal WBC count?
4-10
