blood Flashcards
what are the two major lineages of blood cell?
myeloid and lymphoid
how many different types of blood cell are there?
11
which cells come from the lymphoid lineage?
natural killer cell, t lymphocyte, b lymphocyte, plasma cell
which cells come from the myeloid lineage?
erythrocyte, mast cell, basophil, neutrophil, eosinophil, macrophage (from monocytes), thrombocytes (from megakaryocyte)
which blood cell types end up in the tissue?
mast cells and macrophages
what proportion of the blood is plasma?
55%
what does the plasma of blood contain?
many important components of the blood coagulation (clotting) and immune (fighting infection) systems
Most abundant blood plasma proteins are:
albumin (35-50 g/L), “filler”
Immunoglobulins (15 g/L), involved in fighting infection
fibrinogen (3-5 g/L), involved in clotting
what is the difference between blood serum and blood plasma?
in blood serum the blood is allowed to coagulate before it is centrifuged
Serum = Plasma – Clotting Factors
Plasma = Serum + Clotting Factors (+ clotting inhibitor)
what happens when incompatible blood types are mixed?
antibodies react with antigens on the red blood cell (RBC) membrane, causing haemolysis (RBC rupture)
how are blood groups classified?
based on different antigens (sugars, transmembrane proteins, glycolipids) present on the RBC membrane
what are the most important systems in blood type?
ABO and Rh systems
how is the ABO group classified?
Based on carbohydrate (sugar) antigen present on the RBC membrane
what are the main types of blood group?
AB, A, B, O
which blood type is universal blood donor?
O
which blood type is universal blood recipient?
AB
what happens to the compatibility of blood plasma?
opposite of RBCs
because antibodies are in the plasma
what are the key feature of haemolytic reaction?
Hypotension
Kidney failure
DIC (Bleeding)
what is the Rhesus blood group categorised on?
Based on a transmembrane protein (ion-channel) antigen present on the RBC membrane
what are the two types of rhesus blood group?
Rh+ and Rh-
which rhesus blood group is more common?
Rh+
Ethnicity: Rh- more common in the West (15%) than in Asia or Africa (1%)
what is the most common cause of haemolytic syndrome in newborns and how does it happen?
difference in rhesus blood type
Antibodies from Rh- mother cross placental barrier and cause haemolysis and potentially lethal anaemia in Rh+ foetus/newborn
what are the main causes of thrombosis?
Hypercoagulability Thrombocythaemia (high platelets level) Factor V Leiden Atherosclerosis Cancer
what is neoplasia?
Process of uncontrolled cell growth
what are the two classes of genes implicated with neoplasia?
oncogenes and tumour suppressor genes
how are haematological malignancies classified?
by cell lineage and by location
Leukaemia (blood)
Lymphoma (lymph nodes)
what is polycythaemia?
increased red blood cells
what is Thrombocythaemia?
increased platelets
what is Myelofibrosis?
increased megakaryocytes
what does leukaemia cause?
Accumulation of white blood cells in the bone marrow and blood
bone marrow failure
what effects happen because of bone marrow failure?
Blood hyperviscosity due to increased white cells causing respiratory or neurological symptoms Infection if decreased white cells Tiredness/anaemia Bleeding Bone pain in children
how can lymphoma be classified?
affect T or B lymphocyte
Non-Hodgkin or Hodgkin
(Hodgkin Lymphoma characterised by Reed-Sternberg cells Reed-Sternberg cells generally originate from B lymphocytes, which become enlarged and are multinucleate or have a bilobed nucleus.)
what are the role of growth factors?
direct the transformation of multipotential stem cell into colony forming units (CFU), burst-forming units (BFU) and ultimately specialised blood cells.
what is the role of Colony-stimulating factors?
haemopoiesis of myeloid cells including RBCs
what is the role of lymphokines?
haemopoiesis of lymphocytes and NK cells.
what does iron deficiency cause?
microcytic anaemia Leads to microcytic anaemia (pale and small RBCs) production
what does microcytic anaemia do to RBCs?
smaller than normal and have an increased zone of central pallor increased anisocytosis (variation in size) and poikilocytosis (variation in shape).
what does a B12 or folate deficiency cause?
Megaloblastic anaemia
what does Megaloblastic anaemia do to RBCs?
larger than normal RBCs and includes the formation of macroovalocytes and also may lead to hypersegmented neutrophils
what type of anaemia does blood loss cause?
normocytic anaemia
what does epo do?
It stimulates haemopoiesis of stem cells into erythrocytes (BFU production) in the bone marrow
what causes haemolytic anaemia?
RBC lifespan down from 120 to as little as 20 days
Bone marrow unable to replace sufficient RBCs
how can you get haemolytic anaemia?
either acquired or inherited
acquired can be immune or non-immune
what causes sickle cell anaemia?
Point mutation in the Hb b globin gene Glu 6 to Val
Polymerisation of Hb, distorting RBC
why does sickle cell anaemia cause sickle cell crises?
blockage of microvasculature
what are the two types of thalassemia and how are they caused?
alpha Thalassaemia
Generally large deletions of the a-globin (two a-genes on chrom 16)
beta thalassemia
Point mutations in the b-globin gene
If both genes are affected patient has HbF and b-thalassaemia major
what are the two types of thalassemia and how are they caused?
alpha Thalassaemia
Generally large deletions of the a-globin (two a-genes on chrom 16)
beta thalassemia
Point mutations in the b-globin gene
If both genes are affected patient has HbF and b-thalassaemia major
what does haemostasis prevent?
prevention of severe blood loss after injury