Composition of blood in man

1. COMPOSITION OF BLOOD IN MAN
&
Rh - FACTOR
Dr. J. PRAKASH SAHAYA LEON, M.Sc.,B.Ed.,M.Phil.,Ph.D.,
ASSISTANT PROFESSOR, DEPARTMENT OF ZOOLOGY ,
GOVERNMENT ARTS COLLEGE FOR MEN, KRISHNAGIRI,
TAMILNADU,INDIA
( DEPUTED FROM ANNAMALAI UNIVERSITY)

2. COMPOSITION OF BLOOD IN MAN
 TOTAL BLOOD VOLUME : 5-6 LITERS ( 8% OF BODY
WEIGHT )
 VISCOCITY : 4-5 TIMES THAT OF WATER
 PH (potential of hydrogen) : 7 ± 0.05 ( ALKALINE )
 BLOOD COMPRISES : CELLS, PLASMA
A) CELLS :
CELLULAR ELEMENTS OF BLOOD REPRESENTS 45%
OF THE TOTAL BLOOD VOLUME, CALLED PACKED
CELL VOLUME (PCV) OF HAEMATOCRIT.
CELLULAR ELEMENTS :
 (I) RBC
 (2) WBC
 (3) PLATELETS

3. .
(I) RBC
 ERYTHROCYTES OR RBC - CIRCULAR,
BICONCAVE IN SHAPE
 NON-NUCLEATED DISC
 LIFE SPAN OF RBC IS 120 DAYS.
 THE AVERAGE DIAMETER OF THE CELL IS
ABOUT 7.6 MICRONS
 THICKNESS ABOUT 2.2. MICRONS
 IT CONTAINS THE RESPIRATORY PIGMENT
CALLED HEMOGLOBIN
 NORMAL COUNT : 5 MILLION / MM³

4. (2) WBC
 LEUCOCYTES OR WBC ACT AS PHAGOCYTES THERE BY
CONTRIBUTING
 DEFENCE MECHANISM.
 NORMAL COUNT : 4000-11,000/ MM³ (4-11 X 10³ /MM ³ )
 LEUCOPENIA : LEUCOCYTES (WBC) COUNT DECREASES LESS
THAN 4000/ CU .MM - DUE TO STARVATION,
TYPHOID FEVER, VIRAL INFECTION AND BONE
MARROW DEPRESSION.
 LEUCOCYTOSIS : WHITE BLOOD CELLS COUNT INCREASE ABOVE
11,000 / CU MM – CAUSES STRESS , PREGNANCY,
MENSTRUATION, LACTATION

5. TYPES OF WBC
1) GRANULOCYTES :
 - WBC - WITH GRANULES IN THE CYTOPLASM
 - GRANULOCYTES CONSIST OF NEUTROPHILS ( 50 – 70 % )
 - EOSINOPHILS (1-4 %)
 - BASOPHILS ( 1% )
2) AGRANULOCYTES :
 - WBC - WITHOUT GRANULES IN THE CYTOPLASM
 - AGRANULOCYTES CONSIST OF LYMPHCYTES (20-30%)
 - MONOCYTES (2-8 %)

6. (3) PLATELETS (THROMBOCYTES)
 - SMALLEST BLOOD CELLS
 - COLOURLESS
 - SPHERICLE IN SHAPE
 - THEY PLAY IN IMPORTANT ROLE IN
COAGULATION
 - NORMAL COUNT : 1.4 – 4 LAKHS/MM³

7. B) PLASMA
 - PLASMA IS CLEAR , STRAW COLOURED FLUID OF THE BLOOD
 - REPRESENTS 55% OF THE TOTAL BLOOD VOLUME
 - IT CONTAINS 91% OF WATER , 9 % OF SOLIDS ( 1% INORGANIC
 MOLECULES AND 8% ORGANIC MOLECULES )
MAJOR INORGANIC MOLECULES ARE
- - NA, CL, K , MG, CA,PROTEIN.

8. ORGANIC MOLECULES
 - 7% OF PLASMA PROTEIN
 - 1% OTHER SUBSTANCES LIKE NON-PROTEIN NITROGENOUS, SUGAR,
 FAT, ENZYMES AND HORMONES.
PLASMA PROTEIN :
NORMAL VALUE IS 6.4 –8.3 GM%
 IT CONSISTS OF FOLLOWING COMPONENTS,
 1) 55 % ALBUMIN - 3 to 5 gm%
 2) 38 % GLOBULIN - 0.78 to 0.81 gm%
 3) 7 % FIBRINOGEN - 0.3 gm%
 4) PROTHROMBIN - 40 mg%

9. THERE ARE THREE BROAD GROUPS OF PLASMA PROTEINS IN
HIGHER VERTEBRATES
{ FIBRINOGEN, GLOBULINS, ALBUMIN }
 1)FIBRINOGEN IS RESPONSIBLE FOR BLOOD
COAGULATION
 2)GLOBULINS IS RESPONSIBLE FOR IMMUNOLOGICAL
REACTION AND BLOOD TRANSPORT OF CERTAIN
MOLECULES SUCH AS SOME HORMONES, VITAMINS AND
IRON.
 3)ALBUMIN IS PRESENT ABOUT 55 PERCENT OF THE
PLASMA VOLUME. IT IS TO REQULATE THE COLLOIDAL
OSMOTIC PRESSUER OF THE BLOOD.

10. FUNCTIONS OF BLOOD
 1)RESPIRATORY : EXCHANGE OF O2 AND CO2
 2)NUTRITIVE : CONVEYS ABSORBED FOOD
MATERIALS, GLUCOSE,AMINOACID
 3)EXCRETORY : TRANSPORTS THE METABOLIC
WASTES
 4)BUFFERING ACTION : ( HOMEOSTASIS) MAINTAINING
VOLUME,COMPOSITION, PH

11. FUNCTIONS OF BLOOD
 5)REGULATION OF BODY TEMPERATURE
a) HIGH SPECIFIC HEAT
b) HIGH CODUCTIVITY
c) HIGH LATENT HEAT OF EVAPORATION
 6)CHEMICAL FOR COMMUNICATION AND PROTECTION :
- DEFENCE AGAINST INFECTION, INITIATION OF
INFLAMMATION AND REGULATION OF HEMOSTASIS
( CLOTTING MECHANISM )
 7)PLASMA PROTEINS – FUNCTIONS :
- EXCERT THE OSMOTIC PRESSURE WHICH INFLUENCES
THE EXCHANGE OF FLUID BETWEEN BLOOD AND TISSUES
- ACT AS A RESERVOIR OF PROTEINS.
- COMBINE WITH MANY SUBSTANCES.

12. SERUM
- IF THE BLOOD IS ALLOWED TO CLOT IN A
TEST TUBE, THE CLOT RETRACTS AND
GIVES OUT SERUM
- IT BREAKDOWN PLATELETS DURING CLOTING
BECAUSE SERUM HAS A HIGHER SEROTNIN
(5 HYDROXYTRYPTAMINE – 5HT )

13. Rh FACTOR
- Discovered in Rhesus monkey
 IF MOTHER IS Rh NEGATIVE AND FOETUS IS Rh POSITIVE, SERIOUS
COMPLICATIONS MAY OCCUR. RBC CONTAINING D ANTIGEN( IgD –
IMMUNO GLOBULIN D ) MAY PASS THROUGH PLACENTA FROM THE
FOETUS TO THE MOTHER, EITHER DURING PREGNANCY OR SMALL
AMOUNT OF FOETAL BLOOD LEAKES INTO MATERNAL CIRCULATION AT
THE TIME OF DELIVERY.
 DUE TO THIS, THE MOTHER RESPONDS BY FORMING ANTI-D(antibodies )
against ANTIGEN D, WHICH RETURNS TO SECOND FOETAL CIRCULATION
AND TENDS TO DESTROY FOETAL RBC IF THE SECOND CHILD IS Rh
passitive.( it means the antibodies destroy the antigens of the foetal at second delivary ,
if the child is Rh passsitive ( the Rh passitive is considered as a ANTIGEN ) ) . THIS
KIND OF DISEASE IS CALLED ERYTHROBLASTOSIS FOETALIS.

14. HEMOLYTIC DISEASE
1. IT AFFECTS THE BABIES , Rh- MOTHER and Rh+ FATHER.
2 THE Rh ANTIGEN OF THE BABY ENTERS THE BLOOD OF THE MOTHER. THE
BLOOD OF THE MOTHER PRODUCES Rh ANTIBODY. WHEN THIS ANTIBODY
ENTERS THE FOETUS , THE FOETUS IS AFFECTED.
3. THE Rh ANTIBODY DESTROYS THE RBC OF THE FOETUS
4. THE DESTRUCTION OF RBC LEADS TO HAEMOLYTIC JAUNDICE AND
ANAEMIA
5. THE DEAD RBC ‘s ARE CARRIED TO LIVER FOR DISINTEGRATION. AS MORE
WORK IS GIVEN TO THE LIVER , THE LIVER IS HEAVILY DAMAGED.
6. THIS CAUSES THE DEATH OF THE BABY.

15. PREVENTION OF HAEMOLYTIC DISEASE
 THE DESTRUCTION (destroy) OF Rh+ FOETAL CELLS IN THE MATERNAL
(mother) BLOOD CAN BE BROUGHT ABOUT BY INJECTION OF ANTI-D SOON
AFTER BIRTH (delivery). ( IT CAN PREVENT THE Rh IMMUNIZATION IN THE
MOTHER BODY )
 THE HAEMOLYTIC DISEASE CAN BE WELL PREVENTED SELECTIVE
MARRIAGES. WHEN A LADY HAPPENS TO BE Rh- SHE SHOULD MARRY
ONLY AN Rh- MAN AND NOT AN Rh+ man.
TREATMENT :
 EXCHANGE BLOOD TRANSFUSION SOON AFTER BIRTH i.e REMOVING
SMALL QUANTITIES OF INFANTS BLOOD SUCCESSIVELY FROM
UMBILICAL VEIN AND REPLACING AN EQUAL VOLUME OF COMPATIBLE
Rh NEGATIVE BLOOD.
Souces : Net, University Book, Saras publication

16. BEST WISHES