RED BLOOD CELL AND HAEMATOCRIT

DR NILESH KATE
MBBS,MD
ASSOCIATE PROF
DEPT. OF PHYSIOLOGY
RED BLOOD
CELL.

OBJECTIVES.
 Functional Morphology.
 Red cell Membrane, Composition and
Metabolism
Saturday, November 5, 2016

FUNCTIONAL MORPHOLOGY.
 Normal size, shape & counts
 Variations in size, shape & count.
 Packed cell volume & red cell indices
 Rouleaux formation and erythrocyte
sedimentation rate.

FUNCTIONAL MORPHOLOGY.
 Like other cells
bounded by cell
membrane but Non-
Nucleated.
 Cytoplasm contains
pigmented protein –
Haemoglobin
 It is Chromoprotein –
colour giving protein.

NORMAL SIZE
 Diameter – 7.2 μm (6.9-
7.4)
 Thickness – 2 μm at
periphery & 1 μm at
center
 Surface area – 120-140
μm2
 Volume - 80 μm3
(78-86)

NORMAL SHAPE
 Circular, biconcave disc.
 Advantages of biconcave shape –
 Flexible , capillaries minimum
diameter – 3.5 μm.
 Greater surface area
 Can withstand changes of osmotic
pressure
 Allow easy exchange of O2 & CO2 &
rapid diffusion of other substances.

NORMAL COUNTS
 At birth – 6-7 millions/mm3
 Adult males – 5-6.5 millions/mm3
 Adult females – 4.5-5.5 millions/mm3

VARIATIONS IN SIZE
ANISOCYTOSIS
 Microcytosis
 Iron deficiency anaemia
 Prolonged forced breathing
 Increased osmotic pressure
 Macrocytosis
 Megaloblastic anaemia
 Muscular exercise
 Decreased osmotic pressure.

VARIATIONS IN SHAPE
POIKILOCYTOSIS
 Crenation /shrinkage –
Hypertonic solution.
 Spherocytes – Hypotonic
solutions
 Elliptocytes – anaemias
 Sickle cells – presence of
abnormal haemoglobin (Hb-S)
 Poikilocytes – flask shaped,
hammer shaped

VARIATIONS IN COUNT
PHYSIOLOGICAL
 Increase
 AGE – Newborn more –
hypoxia then decreases
due to physiological
jaundice
 SEX – Males > Females
 HIGH ALTITUDE
 EXCESSIVE EXERCISE
 EMOTIONAL CONDITIONS
 TEMPERATURE - high
 MEALS
 Decrease
 At high barometric
pressure
 After sleep
 In pregnancy
(Haemodilutuion)

VARIATIONS IN COUNT
PATHOLOGICAL
 Increase
 Primary – Myeloproliferative
disoreders
 Secondary – state of chronic
Hypoxia
 Congenital heart disease
 Chronic respiratory disoreders
 Mild haemorrhges
 Phospherous, arsenic
poisoning.
 Decrease
 Anaemia

PACKED CELL VOLUME & RED
CELL INDICES
 Packed cell volume
 Determination of PCV
 Red cell Indices.
 Mean corpuscular volume
 Mean corpuscular Haemoglobin
 Mean corpuscular Haemoglobin concentration.
 Colour index

PACKED CELL VOLUME
 Percentage of the cellular
elements in the whole blood.
 Also called Haematocrit value.
 Normal values in
 Males – 45%
 Females – 42%
 Increases in polycythemia &
decreases in anaemia.

DETERMINATION OF PCV
 Blood mixed with
anticoagulant oxalate &
centrifuged in Haematocrit
tube/wintrobes tube @
3000rpm for 30 min.
 Layers
 Superficial – plasma
 Middle white buffy coat –
WBC & platelets
 Lower – packed RBC.

HAEMATOCRIT VALUES
 Observed Haematocrit –
observed value
 True Haematocrit –
Multiplying by 0.98
 2% plasma trapped in cells
 Body Haematocrit –
Multiplying by 0.87
 Haematocrit for venous
blood is greater than whole
body.

RED CELL INDICES
 Mean corpuscular
volume
Haemoglobin
haemoglobin
concentration.
 Colour index.

MEAN CORPUSCULAR VOLUME
 Average volume of single red
blood cell.
 MCV = PCV x 10
--------------
RBC count/mm3
= 45X10/5 = 90 μm3
Normal value 78-94 μm3
Decreased in Microcytosis
Increased in Macrocytosis

MEAN CORPUSCULAR
HAEMOGLOBIN
 Average weight of haemoglobin in each RBC
 MCH = Hb gm% X 10
-----------------
RBC count/mm3
= 15X10/5X1012
= 30 pg
normal range – 27-33 pg
Increases – Spherocytosis & megaloblastic anaemia
Decreases - anaemia

MEAN CORPUSCULAR
HAEMOGLOBIN CONCENTRATION.
 Amount of Hb expressed as percentage of the volume
of RBC.
 MCHC = Hb gm%
------------------- X 100
PCV/100ml
= 15/45 X 100 = 33.3%
Normal value – 30-33%
Decreases – Iron deficiency anaemia

COLOUR INDEX.
 Ratio of Haemoglobin to RBC
 CI = % of normal Hb
---------------------
% of normal RBC count
= 100/100 = 1
Normal range= 0.85-1.15
Insignificant

ROULEAUX FORMATION AND
ERYTHROCYTE SEDIMENTATION RATE.
 Rouleaux formation.
 Erythrocyte sedimentation rate.
 Methods of determination of ESR.
 Westergren’s Method
 Wintrobe Method.
 Clinical significance of ESR.
 Factors affecting ESR.
 Physiological variations in ESR
 Pathological variations in ESR.

ROULEAUX FORMATION.
 Tendency of RBC to pile one over
the other like coins
 Major Role – Discoid shape &
protein coating.
 Does not occur in circulation due
to plasma proteins
 Reversible phenomenon different
from agglutination where cells are
irreversibly clumped.

ERYTHROCYTE
SEDIMENTATION RATE.
 Def – Rate at which
red cells sediment
when blood containing
anticoagulant is
allowed to stand in
vertical tube.
 Unit – expressed in
mm at the end of 1
hr.

METHODS OF
DETERMINATION OF ESR.
 Westergren’s Method
 Blood with anticoagulant
3.8% sodium citrate in
ratio 4:1 is loaded in
westergren’s tube
vertically upto mark 0 &
allowed to stand for 1 hr.
 Reading is taken at the
end of 1 hr.

METHODS OF
DETERMINATION OF ESR.
 Wintrobe’s Method
 Blood with
anticoagulant is filled in
wintrobe tube with the
help of special pippete
“Pasture pippete” and
then allowed to stand
for 1 hr and reading is
taken at the end of 1 hr.

CLINICAL SIGNIFICANCE OF ESR
PROGNOSTIC TEST
 Normal value
 By Westergren’s
Method
 Males – 3-7mm
 Females – 5-9mm
 By Wintrobe’s
Method

FACTORS AFFECTING ESR.
 Rouleaux Formation – after inflammatory &
neoplastic diseases fibrinogen & other proteins
released favour rouleaux formation & ESR
 Size of RBC – macrocytes raises ESR
 No of RBC- Inverse relationship
 Viscosity of Blood – Inverse relationship

PHYSIOLOGICAL VARIATIONS
IN ESR
 Age – less in infant &
old age
 Sex- males < females
 Mensturation - raised
 Pregnancy – raised.

PATHOLOGICAL VARIATIONS
IN ESR.
 Increase
 Tuberculosis
 Malignant diseases
 Collagen diseases
 All anaemia except
sickle cell anaemia
 Chronic infection.
 Decrease
 Polycythemia
 Decreased fibrinogen
level
 Sickle cell anaemia
 Allergic conditions
 Peptone shock

RED CELL MEMBRANE,
COMPOSITION AND METABOLISM
 Red cell membrane.
 Structure
 Permeability.
 Composition of red blood cells.
 Metabolism of Red blood cells.
 Embden-Meyerhof Pathway
 Hexose monophosphate shunt.
 Utilization of ATP

RED CELL MEMBRANE.
 Trilaminar structure
with bimolecular lipid
layers & 2 layers of
protein.
 Imp Lipids – Glycolipids,
Phospholipids &
cholesterol.
 Proteins – peripheral &
integral.

PROTEINS …….
 Peripheral Protein – rich in lecithin &
sphingomyelin.
 Integral Proteins – anion exchange
protein (Band 3) & Glycophorins (Blood
group antigen)
 Inner surface contains phosphatidylserine
& phosphatidyl ethanolamine
 Shape & flexibility is maintained by
Spectrin, Ankyrin & actin.

PERMEABILITY
 SEMIPERMEABLE
MEMBRANE
 Impermeable to Na, Ca &
Barium ions, fats & sugars
 Slightly to amino acids
 Freely permeable to –
anions Cl-, SO4-,HCO3-,
urea, ammonia alcohol &
bile salts.

COMPOSITION OF RED BLOOD
CELLS.
 Water – 60%
 Haemoglobin – 35%
 Lipids – 5%, lecithin, cephalin & cholesterol.
 Proteins- Glutathiones
 Lipoprotein – elenin (Calvin)
 Enzymes – Glycolytic system, catalase, carbonic anhydrase
 Glucose , amino acids
 Ions – Cl-, PO4-, HCO3- &
 Non-protein nitrogenous substances – urea, NH4, creatine,
uric acid

METABOLISM OF RED BLOOD
CELLS.
 Glucose only fuel used
by RBC
 Embden-Meyerhof
pathway – 90%
glycolysis
 Give 2 ATP
 Hexose-
Monophosphate
shunt- 10% glycolysis

RED BLOOD CELL AND HAEMATOCRIT

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