Introduction to haematology Flashcards
define haematology
biology and pathology of the cells that normally circulate in the blood.
define haemopoeisis
physiological developmental process that gives rise to cellular components of blood.
key properties of a haemopoietic cell.
differentiation into all cell lineages
highly proliferative
self renewal
define symmetric self renewal
stem cell divides into 2 stem cells
define asymmetric self renewal
stem cell divides into 1 stem cell and 1 progenitor cell.
deine lack of self renewal
stem cell divided into 2 progenitor cells
define lack of renewal
maintain stem cell pool with no diffrentiation.
2 lineages of blood cells
myeloid
lymphoid
what types of cells does the myeloid lineage have
WBC, RBC, platelets.
what type of cells does the lymphoid lineage have.
B and T lymphocytes.
what is the difference between a multi potential and pluripotential stem cell.
multi potential stem cells can divide into any time of blood cell..
pluripotential stem cells- are dedicated to either the myeloid and lymphoid lineage but within tho can differentiate into any other cell.
where does haemopoiesis originate
morula- RBC in yolk sac
which region does haemopoiessis start and what day of foetal development
27 days- aorta-gonad mesonephros region.
35-40 days- expand rapidly and then disappear
Inside which organ does haemopoiesis start.
in the liver
what are the functions of a blood cell
oxygen transportation
coagulation
immune response to infection and abnormal cells.
what shape are RBC
donut, biconcave shape.
what is the life span of a RBC
120 days
what terms are used to describe reduced and increased RBC
reduce= anaemia
raised RBC=polycythaemia.
what is the function of WBC
immunity and host defence,
what are the 3 types of granulocytes
neutrophils, basophils, eosinophils.
what is the most common WBC
neutrophils
what is the lifespan of neutrophils
6-8 hrs.
what is increased and decreased neutrophil levels called
increased-neutrophillia.
decreased- neutropenia.
what do eosinophils react to
parasitic infections and alleges
what do neutrophils react to
bacterial infection and inflammation.
what is an increased level of basophils known as, and in which blood cancer does this occur in.
basophillia -Chronic Myeloid Leukaemia
Function of monocytes
phagocytic and antigen presenting cells.
once monocytes reach tissue they are known as
macrophages or histiocytes.
what is increased number of monocytes known as, and in which condition does this happen
monocytosis.
TB
what are monocytes in the liver called
e.g. Kupffer cells in liver
what are monocytes in the skin called
e.g. Langerhans cells in skin
are killer cells part of the innate or adaptive immune system.
innate.
Are B lymphocytes humoral or cellular
humoral.
Are T lymphocytes humoral or cellular
cellular
what cells do T cells interact with
B cells. and macrophages
what is an increase and decreased number of lymphocytes called, and when do these conditions occur.
increased- lymphocytosis (glandular fever, chronic lymphatic leukaemia)
decreased-lymphopenia (post bone marrow transplant)
3 types of lymphocytes
B, T cells and natural killer cells.
what is an increased number of plasma cells known as, and when does this occur.
plasmacytosis- infections and myeloma.
where and what cell are platelets derived from
bone marrow megakaryocytes.
what important process are platelets involve in
clotting.
what is the normal platelet measure in the body
200 x109/litre
what is the normal RBC count in the body
10x109 per litre
what are the 3 important diagnostic tests for blood related problems
FBC, blood film, coagulation screen.
what is shown on a FBC
Hb concentration Red cell parameters MCV (mean cell volume) MCH (mean cell Hb) White cell count (WCC) Platelet count (WCC)
What is the name of the biopsy taken when obtaining bone marrow transplant
trephine
why might test results vary.
– Technical failure e.g. clotted sample, e.g. variation in reagents – Normal Intra-individual – e.g. diurnal variation of cortisol levels Inter-individual – e.g platelet count Abnormal- what is classed as normal.
define reference range
the set of values for a given test that incorporates 95% of the normal population
define sensitivity
TP/ (TP+FN)
defined as the proportion of abnormal results correctly classified by the test
define specificity
TN/ (TN+FP)
defined as the proportion of normal results correctly classified by the test
3 Classification of anaemia
microcytic hypochromic
normocytic hypochromic
macrocytic hypochromic
define microcytic hypchromic anaemia
small MCV and less pigment Hb low, MCH low
what causes microcytic hypchromic anaemia
iron deficiency thalassaemia anaemia of chronic disease lead poisoning sideroblastic anaemia.
what are the MCV and MCH to be classed as microcytic anaemina.
MCV
define normocytic normochromic anaemia
RBC normal in size, MCV/MCH norml, Hb is low
what causes normocytic normochromic anaemia
don’t have enough RBC
haemolytic anaemias anaemia of chronic disease after acute blood loss renal disease mixed deficiencies bone marrow failure (post chemotherapy, infiltration and carcinoma)
what are the MCV and MCH to be classed as normocytic normochromic anaemia
MCV 80-95 fl & MCH ≥ 27 pg
define macrocytic anaemia
RBC large, increased MCV
what is the communists cause of macrocytic anaemiaa
alcohol abuse.
what is the MCV to be classes as macrocytic anaemia
MCV >95 fl
what are the causes of macrocytic anaemias
Megaloblastic: Vitamin B12 or folate deficiency
Non-megaloblastic: alcohol, liver disease, myelodysplasia, aplastic anaemia etc
what do the cells look like on a film in iron deficiency anaemia
Small, pale red cells (low MCV and MCH),
Variable size & shape.
Pencil like cells.
