Haematology Flashcards
What is blood
Blood is specialised fluid composed of cells suspended in a liquid. This liquid is plasma
What is a buffy coat when blood is made to stand still
Platelets + white blood cells
Breakdown of components of blood
Formed elements and plasma
Breakdown of components of formed elements
Red blood cells, white blood cells and platelets
Breakdown of components of white blood cells
Granulocytes and agranulocytes
Breakdown of components of granulocytes
Neutrophils, eosinophils and basophils
Breakdown of components of agranulocytes
Lymphocytes and monocytes
What do developing RBC’s need to mature
B12 and folate
How can changes in cell be detected
Number, higher or lower (blood count)
Appearance on a blood film
What can low haemoglobin suggest
Anaemia
Anaemia classification based on red cell size
Microlytic - Smaller cells due to Iron deficiency
Due to chronic blood loss
Macrolytic - Larger cells due to B12/folate deficiency
Due to excess alcohol, liver disease, hypothyroidism
Normolytic - Normal cell size
Acute blood loss, inflammation or infection
What is anaemia of chronic disease
Inflammation causing anaemia due to changes in iron supply to developing RBC, proliferation of erythroid cells, production of erythropoietin and life span of cells
What can cause a false neutrophilia
Steroidal use can redistribute neutrophils into blood rather than a true increase
Increase in lymphocytes and monoctyes is
Lymphocytosis and monocytosis
Increase in granulocytes
Neutrophilia, eosinophilia and basophilia
Increase in leucocyte number
Leucocytosis
High platelet count
Thrombocytosis
When is thrombocytopenia not genuine
Platelets may clump up in the collection tube
What can cause thrombocytopenia
Liver disease, enlarged spleen (trapping) or excessive consumption such as in autoimmune or fibrin clot
What is haemostasis
Arrest of bleeding and maintenance of vascular patency
Lab assessment of components of plasma
Coagulation proteins (secondary haemostasis) and plasma viscosity
Primary vs secondary haemostasis
Formation of platelet plug - Primary
Formation of fibrin clot - Secondary
Different measures of coagulation time
Prothrombin time (PT) and Activated partial thomboplastin time (aPTT)
What is thromboplastin
Plasma protein aiding blood coagulation through catalyzing conversion of prothrombin to thrombin
Why does prothrombin time shorten faster than activated partial thromboplastin time
As factor VII (measured in PT) has a shorter half life than activated partial thomboplastin time
What helps in fibrinolysis
Plasmin that forms from plasminogen, activated by tissue plasminogen activator
How is fibrinolysis measured
D-dimers which are fibrin degradation products are measured
When can increased fibrinolysis be found
Increased fibrinolysis can be found in thrombosis, inflammation, malignancy and heart failure
