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HAEMATOLOGY AND HAEMOPOIESIS - Coggle Diagram
HAEMATOLOGY AND HAEMOPOIESIS
WHAT IS HAEMATOLOGY
the study of blood
diagnosis and monitoring of diseases
COMMON HAEMATOLOGICAL TESTS
FULL BLOOD COUNT
measured on automated analysers
MEASURED PARAMETERS
Hb (haemoglobin)
RBC (red blood cell count)
WBC (white blood cell count)
platelets
MCV (mean cell volume)
CALCULATED PARAMETERS
HCT (hematocrit) or packed cell volume PCV
MCH (mean cell haemoglobin)
MCHC (mean cell haemoglobin concentration)
blood films
erythrocyte sedimentation rate (ESR)
plamsa viscosity
coagulation screen
HAEMATINIC ASSAYS
iron
ferritin
B12
folic acid
haemoglobin-variant detection
molecular testing
point of care testing
WHAT IS HAEMOPOIESIS
the process by which the cellular elements of blood are formed
WHAT ARE THESE COMPONENTS
RED BLOOD CELLS
most numerous type of cell in blood
normal range 4.0-5.5 x10^12/L
6.7-7.7 um diameter bi-concave disc
contain haemoglobin
carry O2 from lungs and tissue
transport CO2 from tissues to lungs
survival 110-120 days
WHITE BLOOD CELLS
least numerous cells in blood
total white blood count normalised ratio (NR) 3.5-10.0 x10^9/L
5 different types
lymphocytes
NR 1.2-3.5 x10^9/L
fight viral infections
produce antibodies
circulate between blood and lymphatic system
variable life span from a few hours to 4-5 years in the circulation
neutrophils
NR 1.5-7.5 X10^9/L
fight against bacterial infections
3 lobes
fine faint granules
pus cells
phagocytic
half life in circulation 7 hours
eosinophils
NR 0.03-0.60 X10^9/L
two lobes
coarse orange granules
release histamine in allergic reactions
regulate hypersensitivity reactions
effector cells antibody dependent damage to parasites
basophils
NR 150-400 X10^9/L
two lobes
dark coarse azurophilic granules
contain enzymes
moderate inflammatory responses
release heparin and proteases
monocytes
NR 0.2-0.8 x10^9/L
fight bacterial infection
phagocytose bacteria and cells coated with antibodies
precursors of tissue macrophages
life span of up to 70 hours
PLATELETS
NR 150-400 x10^9/L
second most numerous cells in blood
small discoid structures
3-5 um in diameter
life span in circulation 7-10 days
important in blood clotting (haemostasis)
form plug at site of injury
primary haemostasis
initiate secondary haemostasis
SITES OF HAEMOPOIESIS
2 week embryo- yolk sack
12-16 week embryo liver and spleen
at birth - bone marrow, all bones
adult proximal ends of long bones, flat bones
e.g sternum, pelvis and vertebrae
red marrow - active marrow
yellow marrow - inactive marrow
HAEMOPOIESIS INVOLVES
proliferation - multiplication
differentiation - change form
apoptosis - programmed cell death
REGULATION OF HAEMOPOIESIS
regulated by growth factors
2 main classes
colony stimulating factors
interleukins
growth factors inhibit apoptosis
SITES OF PRODUCTION OF HAEMOPOIETIC GROWTH FACTORS
are glycoproteins
produced by
stromal cells
T lymphocytes
liver
kidney
BONE MARROW PRODUCES
1 million red blood cells per minute
similar number of white blood cells and platelets
ALL BLOOD CELLS DEVELOP FROM A HAEOPOIETIC STEM CELL
a cell which gives rise to to all other blood cells
derived from mesoderm
located in the bone marrow
THE HAEMOPOIETIC STEM CELL
a cell that can differentiate into separate cell lineages
rare
perhaps 1:20 million nucleated cells in marrow
exact phenotype unknown
has appearance of small lymphocyte
has ability to renew itself
THE HAEMOPOIETIC STEM CELL
HAS ABILITY TO SELF RENEW
EXACT PHENOTYPE UNKNOWN
NEGATIVE LINEAGE SPECIFIC
CD38-
CD34+
RARE - 1:20 MILLION NUCLEATED CELLS IN MARROW
CAN DIFFERENTIATE INTO DIFFERENT LINEAGES
CAN FIND ITS WAY BACK TO THE BONE MARROW
STAGES IN HAEMOPOIETIC CELL DEVELOPMENT
RENEWAL
⇌
<-- STEM CELL POOL
<-- DIFFERENTIATION
<-- LINEAGE SELECTION
<-- MATURATION
<-- FUNCTION
CELL DEATH (APOPTOSIS)
ERYTHROPOIESIS - RED CELL PRODUCTION
10^12 RED BLOOD CELLS PRODUCED EACH DAY
CONTAIN HAEMOGLOBIN
REGULATED BY ERYTHROPOIETIN
HORMONE
PRODUCED IN KIDNEY
FEEDBACK MECHANISM
EARLIEST ERYTHROID PRECURSOR
PROGRESSIVELY SMALLER NORMOBLASTS BY CELL DIVISION
EARLY
INTERMEDIATE
LATE
NUCLEUS EXTRUDED
RETICULOCYTE
CONTAINS RIBOSOMAL RNA
MATURE ERYTHROCYTE
RED CELL
STAGES OF RED CELL DEVELOPMENT
<-- HAEMOCYTOBLAST
<-- PROERYTHROBLAST
<-- EARLY ERYTHROBLAST
<-- LATE ERYTHROBLAST
<-- NORMOBLAST
<-- RETICULOCYTE
<-- ERYTHROCYTE
RED BLOOD CELLS
FLEXIBLE MEMBRANE
BICONCAVE DISC
SO CAN PASS THROUGH CAPILLARY MICROTUBULES
CAUSE OF DEATH
LOSS OF RED CELL ENZYMES
WHICH MAINTAIN SHAPE AND FLEXIBILITY
DESTROYED BY BONE MARROW, SPLEEN AND LIVER
MUCH OF CELLULAR CONTENT IS RECYCLED
PROTEIN
LIPID
IRON
BREAKDOWN PRODUCTS OF HAEMOGLOBIN EXCRETED THROUGH LIVER, FAECES AND URINE
RBCs UNABLE TO TRAVEL THROUGH THE ENDOTHELIAL MEMBRANE
TYPES OF GRANULOCYTES
NEUTROPHILS
MOST NUMEROUS PERIPHERAL WHITE BLOOD CELLS
LIFESPAN 10 HOURS IN CIRCULATION
MIGRATE PHAGOCYTOSE AND DESTROY BACTERIA
EOSINOPHILS
PRODUCE HISTAMINES IN ALLERGIC REACTIONS
BASOPHILS
MODERATE INFLAMMATORY RESPONSES
RELEASE HEPARIN AND PROTEASES
GRANULOPOIESIS AND MONOPOIESIS
GRANULOCYTES AND MONOCYTES PRODUCED FROM COMMON MYELOID PRECURSORS
REGULATED BY COMBINED ACTIONS OF HAEMOPOIETIC GROWTH FACTORS
IL3
NEUTROPHILS, MONOCYTES AND BASOPHILS
GM-CSF GRANULOCYTE-MACROPHAGE COLONY STIMULATING FACTOR
IL5
EOINOPHILS
GRANULOCYTE MORPHOLOGY
<-- MYELOBLAST
<-- PROMYELOCYTE
<-- MYELOCYTE
<-- METAMYELOCYTE
<-- BAND
NEUTROPHIL
