Haematology - RBCs Flashcards
What is haematocrit?
Volume of RBCs (%)
What is the function of blood plasma?
Carry nutrients, hormones and waste
Maintain fluidity
Maintain intravascular oncotic pressure
Helps clotting
What are the words to describe an increase/decrease in RBCs?
Anaemia
Erythrocytosis
What words desire an increase/decrease in platelets?
Thrombocytopenia
Thrombocytosis
What words describe an increase/decrease in all blood cells (WBCs, RBCs and platelets)?
Pancytopenia
Polycytaemia
If blood sampling takes too long, what forms? What can be used to preserve blood cell morphology?
Platelets clump and form clots
EDTA
What is a haemogram?
Full blood count
Total Hb, haematocrit, blood count, WBCs included
What is an erythrogram?
Test that evaluates red blood cells
What 3 processes cause anaemia?
Inadequate erythropoiesis
Haemolysis (increased RBC destruction)
Increased blood loss
What is blood loss anaemia? What can cause it?
Loss of all blood components (all cells and plasma)
Haemorrhage (internal or external)
Blood sucking parasites
With blood loss anaemia, does HCt and TP change?
No - proportional loss of all blood components
Within a few hours, what does the body do in response to blood loss anaemia?
Influx of water from extravascular space - diluted blood, decreased HCt and TP
Blood loss anaemia can be acute or chronic. What compensates for acute blood loss anaemia? How long does this take?
Bone marrow- able to increase erythropoiesis
Lag of few days as young RBCs are in circulation, back to normal within 1-2 wks
What can chronic blood loss anaemia lead to? What effects does this have on haematopoiesis?
Iron deficiency anaemia (IDA)
Iron required for erythropoiesis - decreased
Haemolysis can be extravascular or intravascular. Which is more severe? Why?
Intravascular more severe
Cause release of free haemoglobin
What cells mediate extravascular haemolysis?
Macrophages in liver, spleen and bone marrow
Describe the basic degradation of haemoglobin
Haemoglobin Haem Haemoverdin Haemobilirubin Hameosiderin
What can cause intravascular haemolysis?
Complement system (immune mediated) Oxidative damage (non-immune mediated) Mechanical injury (non-immune mediated)
What can free haemoglobin cause?
Hyperbilirubinaemia jaundice (liver overwhelmed by bilirubin) Haemoglobinuria
Anaemia can be mild, moderate or severe. It can also be classed on regenerative response. What are the 2 types? What cells are counted to diagnose this?
Regenerative - presence of polychromasia and reticulocytes
Non-regenerative - no polychromasia/reticulocytes
What can cause regenerative and non-regenerative anaemia?
Regenerative - blood loss, haemolysis
Non-regenerative - iron deficiency, bone marrow disease, immune disease, chronic inflammation etc
What is mean corpuscular volume (MCV)?
Average size of RBC
Anaemia can be classed based on MCV (increased cell size). What are the names of anaemia with decreased, normal and raised MCV
Normal - normocytic anaemia
Reduced - microcytic anaemia
Increased - macrocytic anaemia
Anaemia can be based on mean corpuscular Hb concentration (average RBC Hb conc). What is this called if it is normal, reduce or raised?
Normal - normochromic anaemia
Lowered - hypochromic anaemia
Raised = artefact!!
What does hypochromic anaemia suggest a deficiency in?
Iron
What type of regeneration/non-regneration does microcytic anaemia suggest?
Regenerative anaemia
Reticulocytes are larger
What are immature RBCs with organelles and a nucleus called? What about immature RBCs without a nucleus?
Erythroblast - contain nucelus and organelles
Reticulocytes - large blue
What is found in reticulocytes? (The 3 Rs)
RER
Ribsosomes
RNA
What does polychromasia suggest?
Regenerative anaemia
Abnormal immature RBCs in blood - blue colour
What are the 2 distribution abnormalities of red blood cells? What do these mean? Are they normal?
Agglutination - by antibodies, always pathological
Rouleaux formation - stacking on top of each other, can be normal in horse and cat
Rouleaux formation of RBCs can be normal in horses and cats. In other species, what may it indicated?
Inflammation
Neoplasia
What is the presence of abnormally shaped RBCs called?
Poikilocytosis
Blood cells can undergo crenation (shrinkage to abnormal shape). What are these cells called? What do they look like?
Echinocytes
Short, evenly spaced points
What may cause echinocyte present in a blood smear?
Artefact
Uraemia
What are small round RBCs called? What does this strongly suggest?
Spherocytes
Immune mediated haemolytic anaemia (IMHA)
How does IMHA cause RBCs to become spherocytes?
Partial phagocytosis of RBC
Loss of disc shape
