DR NILESH KATE

MBBS,MD ASSOCIATE PROF

DEPT. OF PHYSIOLOGY

RED BLOOD CELL.

OBJECTIVES. Functional Morphology. Red cell Membrane, Composition and

Metabolism

Monday, May 1, 2023

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

sedimentation rate.

Monday, May 1, 2023

FUNCTIONAL MORPHOLOGY. Like other cells

bounded by cell membrane but Non-Nucleated.

Cytoplasm contains pigmented protein – Haemoglobin

It is Chromoprotein – colour giving protein.

Monday, May 1, 2023

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)

Monday, May 1, 2023

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.

Monday, May 1, 2023

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

Monday, May 1, 2023

VARIATIONS IN SIZE ANISOCYTOSIS

Microcytosis Iron deficiency anaemia Prolonged forced breathing Increased osmotic pressure

Macrocytosis Megaloblastic anaemia Muscular exercise Decreased osmotic pressure.

Monday, May 1, 2023

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

Monday, May 1, 2023

VARIATIONS IN COUNTPHYSIOLOGICAL

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)

Monday, May 1, 2023

VARIATIONS IN COUNTPATHOLOGICAL

Increase Primary – Myeloproliferative

disoreders Secondary – state of chronic

Hypoxia Congenital heart disease Chronic respiratory disoreders Mild haemorrhges Phospherous, arsenic

poisoning.

Decrease Anaemia

Monday, May 1, 2023

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

Monday, May 1, 2023

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.

Monday, May 1, 2023

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.

Monday, May 1, 2023

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.

Monday, May 1, 2023

RED CELL INDICES Mean corpuscular

volume Mean corpuscular

Haemoglobin Mean corpuscular

haemoglobin concentration.

Colour index.

Monday, May 1, 2023

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

Monday, May 1, 2023

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

Monday, May 1, 2023

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

Monday, May 1, 2023

COLOUR INDEX. Ratio of Haemoglobin to RBC

CI = % of normal Hb

---------------------

% of normal RBC count

= 100/100 = 1

Normal range= 0.85-1.15Insignificant

Monday, May 1, 2023

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.

Monday, May 1, 2023

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.

Monday, May 1, 2023

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.

Monday, May 1, 2023

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.

Monday, May 1, 2023

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.

Monday, May 1, 2023

CLINICAL SIGNIFICANCE OF ESRPROGNOSTIC TEST

Normal value By Westergren’s

Method Males – 3-7mm Females – 5-9mm

By Wintrobe’s Method

Monday, May 1, 2023

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

Monday, May 1, 2023

PHYSIOLOGICAL VARIATIONS IN ESR

Age – less in infant & old age

Sex- males < females Mensturation - raised Pregnancy – raised.

Monday, May 1, 2023

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

Monday, May 1, 2023

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

Monday, May 1, 2023

RED CELL MEMBRANE. Trilaminar structure with

bimolecular lipid layers & 2 layers of protein.

Imp Lipids – Glycolipids, Phospholipids & cholesterol.

Proteins – peripheral & integral.

Monday, May 1, 2023

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.

Monday, May 1, 2023

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.

Monday, May 1, 2023

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

Monday, May 1, 2023

METABOLISM OF RED BLOOD CELLS.

Glucose only fuel used by RBC

Embden-Meyerhof pathway – 90% glycolysis Give 2 ATP

Hexose-Monophosphate shunt- 10% glycolysis

Monday, May 1, 2023

Thank You