Flashcards in Introduction to haematology Deck (34):
What is haemopoiesis?
Physiological developmental process giving rise to cellular components of blood
What is the first cell in haemopoiesis?
Haemopoietic stem cell
What are the 4 facts of haemopoietic stem cells?
Symmetric self renewal - increase stem cell pool, no generation of differentiated progeny
Asymmetric self renewal - maintenance of stem cell pool and generation of differentiated progeny
Lack of self renewal - increased generation of differentiated progeny, reduced stem cell population
Lack of self renewal - maintenance of stem cell pool RESTING STATE
What are the characteristics of haemopoietic cells that make them suited for their function/
Differentiation potential for all lineages
High proliferative potential
Long term activity throughout lifespan
What are the 2 broad lineages of haemopoiesis?
Myeloid - granulocytes, erythrocytes, platelets
Lymphoid - B lymph, T lymph, NK cells
When does haemopoiesis first start and where?
AGM (aorta gonad mesonephros)
At day 40, haemopoiesis disappears at the AGM, why?
Migration of haemopoietic stem cells from AGM to foetal liver (which becomes site of haemopoiesis)
What is the lifespan of a erythrocyte?
What do the following terms mean?
-Reduced plasma volume (therefore ratio of RBC:plasma increases)
What is the term meaning reduced number of neutrophils?
What is the term meaning increased neutrophils?
How long do neutrophils last in the bloodstream?
What circumstances does eosinophilia occur?
What condition could basophilia indicate?
Chronic myeloid leukaemia
What is the term meaning increased number of monocytes?
What could increased number son monocytes in the blood indicate
Infection e.g. TB
What do Natural killer cells do?
Large granular cells (innate immunity) that recognise non-self cells
What are the function of B lymph?
Part of adaptive immune system, they rearrange immunoglobin genes to enable specific antibody production
What are the function of T cells?
T helper and Cytotoxic T cells
What does lymphocytosis mean?
Increased number of lymphocytes
e.g. atypical lymphocytes of glandular fever; chronic lymphocytic leukaemia
What does lymphopenia mean?
Reduced number of lymphocytes e.g. post bone marrow transplant
What does plasmacytosis mean?
Increased number of plasma cells e.g. infection, myeloma
What cells do platelets cells originate from?
What are the 4 main subdivisions of haematology?
What information can you get from a FBC?
Red blood cell count
- Mean cell volume
- mean cell Hb
White blood cell
What are the normal FBC ranges?
Hb (g/l)male = 135-180; F 115-160
Platelets - 150-400
MCV - 78-100
MCH - 27-32
What tis the information you receive from a coagulation screen?
Activation partial thromboplastin time
When blood is extracted, how is it treated in the tube?
What is meant by test sensitivity?
Degree to which tests picks up TRUE ABNORMALITIES (i.e. true negatives)
What does test specificity tell us?
The proportion of normal test results correctly classified by a test
What are the three main types of anaemia?
Microcytic (smaller), homochromic (paler)- (low MCV, MCH)
(normal MCV, MCH, but actual Hb is low)
What can cause microcytic hypo chromic anaemia?
What can cause normocytic, norochromic anaemia?
Acute blood loss
Bone marrow failure
Mixed deficiencies (folate, B12, iron)