THE PHYSIOLOGY OF BLOODAN INTRODUCTION AND OVERVIEW By Dr.M.ANTHONY DAVID, MD.NOMAD:2005: BP: INTROVERVIEW 1

WHAT IS BLOOD?

IT IS A LIQUID CONNECTIVE TISSUE IN AN AVERAGE 70 Kg MAN:

100 Trillion cells. Of which 25 trillions are Red Blood Cells! The average blood volume is 5 6 lts. It is roughly 7% of the total body weight.NOMAD:2005: BP: INTROVERVIEW 2

HEMATOL OGY: TH E S TU DY OF B LOOD MAD E POSSIBLE BY MIC ROSCOPY

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THE COMPOSITION OF BLOOD PLASMA

The Liquid: Plasma:

Water, the solvent The solute:

Proteins:

BLOOD PLASMA

Albumin Globulins:# Fibrinogen Na+ K+ Ca++ Urea Glucose LipidsWATER SOLUTES

Electrolytes:

PROTEINS ELECTRO -LYTES ORGANIC MOLECULES 4

Organic molecules

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THE FORMED ELEMENT: CELLSBLOOD CELLS

ERYTHROCYTES

LEUCOCYTES

THROMBOCYTES

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BLOOD: COMPOSITION

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FUNCTIONS OF BLOOD

NUTRITIVE RESPIRATORY EXCRETORY BODY DEFENCE: IMMUNITY TRANSPORT:

HORMONES VITAMINS DRUGSNOMAD:2005: BP: INTROVERVIEW 7

BLOOD:TRANSPORTING HORMONE MOLECULES

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OXYGEN & CO2 TRANSPORT

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FUNCTIONS OF BLOOD

HOMEOSTATIC FUNCTION:

ACID BASE BALANCE. ELECTROLYTE BALANCE. HEMOSTASIS. THERMOREGULATION.

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WHAT IS BLOOD VOLUME?The total amount of blood in circulation plus the amount of blood in the reservoirs constitutes the Blood Volume The average adult 70 kg man has a blood volume of 5 to 6 litres.NOMAD:2005: BP: INTROVERVIEW 11

EXPRESSION OF BLOOD VOLUME

Usually Blood Volume is expressed in liters. It can also be expressed in relation to body weight.

It is 7% Body Weight

Another way to express it is in terms of Body Surface Area.

Whole Blood : 2.8 Lts/M2 Plasma : 1.5 Lts/M2NOMAD:2005: BP: INTROVERVIEW 12

METHODS OF MEASURING BLOOD VOLUME

IN HUMANS: ONLY INDIRECT METHODS DYE DILUTION TECHNIUE: PRINCIPLE:

Injection of a known volume of non toxic substance into the circulation. Measuring the dilution of this injected dye after some time. This gives us the Plasma volume.NOMAD:2005: BP: INTROVERVIEW 13

DYE DILUTION TECHNIQUE

V1 = VOLUME C1 = CONCENTRATION OF DYE

V2 = VOLUME C2 = CONC. OF DYE

V1 X C 1 = V 2 X C 2 OR V2 = V1 X C 1 = Amount of Dye injected C2 Conc. Of the dye in the PlasmaNOMAD:2005: BP: INTROVERVIEW 14

HEMATOCRIT (PCV)The volume of erythrocytes in the whole blood expressed in percentage is the Hematocrit. This is also called as Packed Cell Volume or PCV. This is determined by the Wintrobes tube, using a Centrifuge.NOMAD:2005: BP: INTROVERVIEW

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HEMATOCRIT

A mixture of blood and double oxalate (K NH4) is taken upto 100 mark in the Wintrobes tube. The tube is placed in the centrifuge. It is rotated at 3,000 rpm for 30 minutes. The Hematocrit is then read off the tube. Blood Volume = Plasma Volume X 100 NOMAD:2005: BP: INTROVERVIEW 16 100 - PCV

HEMATOCRIT

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BLOOD VOLUME: PHYSIOLOGICAL VARIATIONS AGE SEX TEMPERATUR E BODY WEIGHT BODY SURFACE

PREGNANCY EXERCISE POSTURE HYPOXIA EMOTIONS18

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BLOOD VOLUME & AGEAGE AT BIRTH 6 Months 1 year 2yrs 6 months 4 years 7 years 10 years ADULTS BLOOD VOLUME in Liters 0.3 0.5 0.7 1.0 1.3 1.7 2.5(Girls); 3.2 (Boys) 5 (Men) 4.5 (Women)

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BLOOD VOLUME: PHYSIOLOGICAL VARIATIONS1. SEX:

Males have more blood volume than females. Acute exposure to cold causes reduction in blood volume due to Plasma water loss to tissues.NOMAD:2005: BP: INTROVERVIEW 20

2. TEMPERATURE:

BLOOD VOLUME: PHYSIOLOGICAL VARIATIONS3. BODY WEIGHT: It is usually 7% of the Body Weight. 4. BODY SURFACE AREA: 2.8 Lts/Square Meters of BSA

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BLOOD VOLUME: PHYSIOLOGICAL VARIATIONS5. PREGNANCY:

Increases by 20 30% due to mass of fetus. Vigorous exercise causes an increase. Changing from lying down to erect.NOMAD:2005: BP: INTROVERVIEW 22

6. EXERCISE:

7. POSTURE:

BLOOD VOLUME: PHYSIOLOGICAL VARIATIONS8. HYPOXIA:

Seen in High altitudes. Erythrocytes So Blood volume. Excitement causes an increase in the Blood volume.23

9. EMOTIONS:

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BLOOD VOLUME: PATHOLOGICAL VARIATIONSDECREASE IN BLOOD VOLUME IS HYPOVOLEMIA. CAUSES: 1. BLOOD LOSS: 2. SHOCK: Crushing Injury Cardiogenic Neurogenic Psychogenic.NOMAD:2005: BP: INTROVERVIEW 24

HYPOVOLEMIA: CAUSES (contd)3. HEMOLYSIS:

Mismatched transfusion Snake bite Black water fever Hemorrhagic Plagues/Dengue MeaslesNOMAD:2005: BP: INTROVERVIEW 25

HYPOVOLEMIA: CAUSES (contd)4. DEHYDRATION:

Diarrhoea Cholera Gastroenteritis Burns Hyperemesis.

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HYPOVOLEMIA: CAUSES (contd)5. ANEMIA:

Decreased RBC volume Plasma may increase. Blood volume per body weight decreases though Blood volume per BSA may be normal. Decrease in Blood volume.

6. OBESITY:

7. HYPOTHYROIDISM (MYXEDEMA):

8. ACUTE COLD: Decreases blood volume. NOMAD:2005: BP: INTROVERVIEW

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TREATMENT FOR BLOOD LOSSTRANSFUSION OF WHOLE BLOOD OF THE SAME BLOOD GROUP & TYPE. INFUSION OF PLASMA INFUSION OF DEXTRAN OR NORMAL SALINE.NOMAD:2005: BP: INTROVERVIEW 28

HEMOPOIESIS & ERYTHROPOIESISBy Dr. M.Anthony David.MD.

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HEMOPOIESIS: INTRO

Hemo: Referring to blood cells Poiesis: The development or production of The word Hemopoiesis refers to the production & development of all the blood cells:

Begins in the 20th week of life in the fetus & continues in the red bone marrow till death.NOMAD:2005: BP: INTROVERVIEW 30

Erythrocytes: Erythropoiesis Leucocytes: Leucopoiesis Thrombocytes: Thrombopoiesis.

STEM CELL THEORY

All blood cells are produced by the bone marrow. They come from a single class of primitive mother cells called as: PLURIPOTENT STEM CELLS. These cells give rise to blood cells of:

Myeloid series: Cells arising mainly from the bone marrow. Lymphoid series: cells arising from lymphoid tissues.NOMAD:2005: BP: INTROVERVIEW

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PROGENITOR CELLS

Committed stem cells lose their capacity for self-renewal. They become irreversibly committed. These cells are termed as Progenitor cells They are regulated by certain hormones or substances so that they can:

Proliferate Undergo Maturation.

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BLOOD CELLS: DEVELOPMENTPROG ENI TOR CE LL S

LY MPHO ID PRO MEGA MYELO BLA ST MONOBL AST CE LLS NORMOBL AST KA RYO BL AST

LYMP HO CY TESERYTHROCYTESTH ROMB OCY TES GRANUL OCYTE S MONOCYTE S

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ERYTHROPOIESIS: SITES/PHASES

INTRA UT ER INE LIF E:

INTRAVASC UL AR PH ASE : Up to 3 rd mo nth of Intr a U te ri ne Life.

End ot helial cell s = = = RBCs

HEPATI C P HAS E : 3 rd t o 5 th mo nth IU LLi ver & Sp lee n nR BCs from M ese nchymal cell s.

MYEL OI D PH ASE : Fr om 5 th m onth of IUL onwar ds.NOMAD:2005: BP: INTROVERVIEW 34

ERYTHROPOIESIS: SITES/PHASES contd.

POST NATAL LIFE:

CHILDREN:

Predominantly Red Bone Marrow of skeleton:Axial & Appendicular.

ADULTS:

Red Bone Marrow of Axial Skeleton.

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ERYTHROPOIESISPROERYTHROBLAST BASOPHILIC ERYTHROBLAST POLYCHROMAT OPHILIC ERYTHROBL AST ORTHOCHROMATIC ERYTHROBLAST

RETICULOCYTE

MATURE ERYTHROCYTESNOMAD:2005: BP: INTROVERVIEW 36

FACTORS REGULATING ERYTHROPOIESIS

SINGLE MOST IMPORTANT REGULATOR: TISSUE OXYGENATION BURST PROMOTING ACTIVITY ERYTHROPOIETIN IRON VITAMINS:

Vitamin B12 Folic Acid

MISCELLANEOUSNOMAD:2005: BP: INTROVERVIEW 37

ERYTHROPOIETIN

A hormone p ro duced by the Ki dn ey. Now adays a vailabl e a s Syn thet ic Epo ie ti Incre as es the n umbe r of :

Nucl eate d p recur so rs i n t he m ar ro w. Ret icul ocyte s & Matur e Er yth rocyte s i n the blood .

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VITAMINS

B 12 : Cya noco ba la mi ne & Fol ic Ac id:

Is also cal led Ex tr insi c Facto r of Ca stle . Needs th e Intr insi c Facto r from th e Gastri c j ui ce for ab so rpti on f rom S mal l Inte sti ne. De ficiency cause s Per nicious (Wh en I F is mi ssi ng) o r Me gal ob lasti c An emi a. Sti mulat es Er yt hrop oiesis Is foun d in meat & diar y prod ucts.NOMAD:2005: BP: INTROVERVIEW 39

IRON

Esse ntia l f or the synthe si s o f Hem og lo bin . Def icie ncy ca use s Microc yti c, Hypoc hro mic A nemi a. Def icie ncy ca use s the c ommone st typ e o f Anem ia .

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