It is basically connective tissue in fluid form. It
is called as the fluid of life, as it carries
oxygen from lungs to all parts of the body
and carbondioxide from all parts of the body
to the lungs.
Color: Scarlet red and Purple red
Volume: In new born-450 ml
Normal healthy male adult-5L
3) pH: Slightly alkaline 7.4
4) Specific Gravity: Total blood- 1.052-1.061
5) Viscosity: 5 times more than water
COMPOSITION OF BLOOD
• RED BLLOD CELLS
• WHITE BLOOD CELLS
Plasma is the straw colored liquid component of blood.
It contains 90-92% 0f water and 8-9% of solids.
These solids are the organic and inorganic substances.
The removal of coagulation factors from plasma leaves
a fluid similar to interstitial fluid, known as serum.
Within 45 minutes of clot formation serum oozes out
of the clot
It is different from plasma only by the action of
Serum = Plasma - Fibrinogen
FUNCTIONS OF BLOOD
Transport Of Hormones And Enzymes
Regulation of Acid-Base Balance
Regulation of body Temperature
In embryonic stage plasma cells are synthesized by
mesenchymal cells where as in adults they arise from
reticuloendothelial cells of liver and also from spleen,
•Role in blood coagulation( Fibrinogen).
•Role in Defense Mechanism: γ-globulins act as
antibodies, also called immunoglobulins
•Role in transport mechanism: Albumin,α and β-
globulins are responsible for the transport of hormones
Functions Of Plasma Proteins
•Role in viscosity of blood: Plasma proteins provide
viscosity which is essential for maintaining BP. Albumin
provides maximum viscosity.
•Role in ESR: globulin and fibrinogen accelerate
rouleaux formation, which in essential for ESR.
•Role as reserve proteins: Act as last source of energy in
case of starving or inadequate food intake
RED BLOOD CELLS
RBCs also called as erythrocytes are non
nucleated formed elements of the blood.
There red color is due to hemoglobin
Males: 5 million/cu mm
Females: 4.5 million/cu mm
SHAPE AND SIZE
• Normally disk shaped &
• Central portion thinner
and periphery thicker.
• Size: Diameter = 7.2μ
• At periphery=2.2 μ
• At center = 1 μ
When blood is taken
out, RBC pile up one
above another like
pile of coin. This
property of the red
blood cells is called
Transport of oxygen from lungs to tissues:
Hemoglobin + oxygen = oxyhemoglobin
Transport of carbon dioxide from tissues to lungs:
Hemoglobin + carbon dioxide = carbhemoglobin
In determination of blood groups:
Carries blood group antigens like antigen A,B etc. that
help in determination of blood groups & enables to prevent
reactions due to incompatable blood transfusion
Functions of RBC’s
Variations in Number of
1INCREASE IN NUMBER
2DECREASE IN NUMBER
Increase In Cell Count
An increase in the red blood cell count is known as
At birth, the red blood cell count is 8-10 millions/cu mm
of blood. The count decreases within 10 days after birth
due to destruction of cells causing physiological
jaundice in some infants.
Before puberty and after menopause in females the RBC
countis similar to that of males.
3. High altitude
The inhabitants of mountains have an increased red blood
cell count of more than 7 millions/cu mm.
4. Muscular Exercise
There is a temporary increase in red blood cell
count after exercise.
5. Emotional Conditions
The red blood cell count is increased during the
emotional conditions like anxiety.
6. Increased Environmental Temperature
The rise in the atmospheric temperature causes elevation of
red blood cell count.
7. After Meals
There is a slight increase in the red blood cell count after
Decrease in cell count
1. High barometric pressures
At high barometric pressures, when the oxygen tension of
blood is higher than the normal, the red blood cell count is
2. During sleep
The count of red blood cells is slightly reduced during sleep.
In pregnancy, the red blood cell count is less because of
increase in extracellular fluid volume. 23
RBC count >7 millions/cu mm of the blood.
1) Primary Polycythemia
2) Secondary Polycythemia
PRIMARY POLYCYTHEMIA -
Polycythemia Vera is a disease with persistent
increase in red blood cell count above 14 millions/cu
mm of blood.
This is always associated with increased white blood
cell count above 24,000/cu mm of blood.
Polycythemia vera occurs in disorders like
malignancy of red bone marrow.
This is secondary to some of the pathological
conditions (diseases) such as:
• Respiratory disorders like emphysema.
• Congenital heart disease.
• Chronic carbon monoxide poisoning.
• Poisoning by chemicals like phosphorus and
Variations In Shape Of RBC
1. CRENATION-shrinkage as in hypertonic solution
2. SPHEROCYTOSIS-Globular form as in hypotonic
3. ELLIPTOCYTOSIS-Elliptical shape in certain anemia's
4. SICKLE CELL-cresent shape as in sickle cell anemia
5. POIKILOCYTOSIS-unequal shape due to deformed cell
membrane. the shape can be flask, hammer or any
other unusual shape.
Variations In Structure Of RBC
1. PUNCTATE BASOPHILISM-dots of basophilic
material(porphyrin) appear in the red blood cells
giving a stripped appearance.
This occur in conditions like lead poisoning
2.RING-a ring or twisted strands of basophilic material
appear in the periphery of the RBCs.It is also called as
It is present in certain type of anemia.
3 HOWEL –JOLLY Bodies-in certain anemia's
some nuclear chromatin fragments are present
in RBCs.(in splenectomy pts.)
4- HEINZ-bodies- they are seen in G6PD
deficiency. They represent denatured globin
chains when there is not enough G6PD
around, the bonds between heme and globin
are attacked. Heme is just recycled, but
globin chain become denatured, forming a
little ball that stick to the inside of red cell
Life span of R.B.Cs
•Average life span of RBCs is about 120 days. They
are destroyed in reticuloendothelial system.
•When cell became older the cell membrane became
•Destruction occurs mostly in capillaries of spleen.
•Spleen is called as GRAVEYARD OF R.B.C.s
Hemolysis & Fragility of
Hemolysis: destruction of formed elements of
blood/breakdown of RBC’s to liberate hemoglobin
Fragility: it is the susceptibility of RBC’s to hemolysis
Process of hemolysis
Normally plasma and RBC’s are in equilibrium, but
when this equilibrium is disturbed the cells get effected.
Conditions when haemolysis occurs:
•Poisoning by chemicals/toxins
These are the substances that cause destruction of RBC’s
These can be of 2 types
Chemical substances : alcohol ,benzene, chloroform ,
Substances of bacterial origin: toxins from bacteria and
venom of poisonous snakes
Fate of RBC’s
Destruction of RBC’s in spleen
Release of hemoglobin
Stored & reused
Stored & reused
It is the process of origin, maturation and development
Hemopoiesis is the process of origin development and
maturation of all the blood cells.
Sites of Erythropoiesis
IN FETAL LIFE: erythropoiesis occurs in different sites at
• Mesoblastic stage: during first trimester of
intrauterine life, RBC’s are produced from
mesenchymal cells of the yolk sac.
• Hepatic stage: during second trimester, RBC’s are
produced from the liver. Some cells are also
produced from spleen and lymphoid organs also.
• Myeloid stage: during third trimester, RBC’s are
produced from red bone marrow & liver.
IN NEW BORN BABIES AND ADULTS:
• Upto the age of 20 years: bone marrow of all
• After the age of 20 years: all membranous
bones and ends of long bones
•Hemoglobin - Structure Content : It is composed of
the protein globin (a polypeptide), and the pigment
• The hemoglobin has the ability to combine with
oxygen is due to the four iron atoms associated with
each heme group within the molecule.
• A heme group consists of an iron (Fe) ion held in a
heterocyclic ring, known as a porphyrin.
•This porphyrin ring consists of four pyrrole molecules
cyclically linked together (by methine bridges) with the
Iron ion bound in the centre.
•Hemoglobin (Hb) is a chromoprotein.
•Molecular weight 64,458 Dalton
•Each hemoglobin molecule caries four molecule of
oxygen and each gram of hemoglobin can carry 1.34
•About 6.25 grams of hemoglobin is synthesized each
day to replace the hemoglobin lost due to normal
destruction of RBCs
•Synthesis begin from proerythroblast to reticulocyte.
Average Hb content of blood is= 14-16gm/dl.
Varies with age and gender.
At the time of birth, in infants and growing children
the RBC count is more and so is the hemoglobin
In adult males-14-16gm%
In adult females-12-14.5gm%
Two types :
Adult (Hb A): the globin contains two alpha
and two beta chains and has less
affinity to oxygen
Fetal (Hb F):there are two alpha and two
gama chains and has more
affinity for oxygen
METHODS OF ESTIMATION
Based on color of hemoglobin or derivative of hemoglobin
Based on specific gravity
Based on iron content of hemoglobin
Based on oxygen combining capacity of hemoglobin.
Based on measurement using spectrophotometric devices.
E S R
ESR is the rate at which the erythrocytes settle down.
When mixed with an anticoagulant and allowed to stand
undisturbed in a vertical tube, the RBC’s settle down
due to gravity With a supernatant layer of clear plasma.
Two ways of determination
i. Westgren’s tube is used.
ii. 300 mm long tube, opened on both ends.
iii. Marked from 0-200 mm from above downwards
iv. 1.6 ml of blood is mixed with 0.4 ml of 3.8%
v. The blood is loaded up to 0 mark above the tube
vi. The reading is taken thereafter.
i. Wintrobe’s tube is used
ii. It is a short tube, opened at one end
iii. It is 110mm long with 3mm bore
iv. Determines ESR & PCV
v. It shows marking on both sides, from 0-100(ESR)
vi. 1ml of blood is mixed with ethylene-di-amine-
vii. Blood is loaded up to 0 mark above
Normal values of ESR
BY WESTERGREN’S METHOD:
In Males = 3-7 mm in 1 hr.
In Females = 5-9 mm in 1 hr.
Infants = 0-2 mm in 1 hr.
BY WINTROBE’S METHOD:
In Males = 0-9mm in 1 hr.
In Females = 0-15mm in 1 hr.
Infants = 0-5 mm in 1 hr.
Raised in following
•Sickle cell anaemia
In Males = 40-45%
In Females = 38-42%
White Blood Cells
• Also known as WBC’s or leucocytes
• Colorless and nucleated formed elements of blood
• Comparatively large in size and lesser in number
• Play a role in defense mechanism of body
•Also known as polymorphonuclear
the nucleus is multilobed
•The number of lobes varies from 1-
•With Leishman’s stain, the granules
Electr. Micros. view
•Granules appear violet in color
•Ameboid and phagocytic in nature
Along with monocytes neutrophils provide Ist line of
They wander freely through out the body.
Mechanism of action:
Released in large number from the blood.
Move by diapedesis to the infection site by means of
Each neutrophil can hold upto 15-20 micro-organism
at a time.
Start destroying the bacteria by means of
• Coarse large granules that stain
pink with eosin.
• Nucleus is bilobed (spectacle
Elect. Micros. view
Provides defense against parasitic
infections and allergic conditions.
They are responsible for detoxification,
disintegration and removal of foreign
Mechanism of action:
Attack the invading organism by secreting cytotoxic
These substances are lethal and destroy the parasites
They are eosinophil peroxidase,major basic protein
(MBP), eosinophil derived neurotoxin and interleukin 4
• Also have Coarse large
• Stain purple blue with
• Nucleus is bilobed
• Diameter = 8-10μ
Elect. Micros. view
These play an important role in
healing process and acute
Mechanism of action:
Basophils execute functions by releasing important
substances from their granules such as heparin and
histamines,proteases and myeloperoxidases and
• Largest WBC’s, Diameter = 14-18μ
• Cytoplasm clear without granules
• Nucleus is oval, bean shaped or kidney
• Nucleus is in the center pushed to one
• Large amount of cytoplasm is seen
These are the largest cells among the WBC’s.
Like neutrophils they are motile and phagocytic in
They are the precursors of the tissue macrophages.
Matured monocytes stay in blood for few hours.
After which they enter the tissues and become tissue
These act by secreting substances like interleukin-1,
colony stimulating factor and platlet activating factor.
Mechanism of action:
• Cytoplasm clear without granules
• Nucleus is oval, bean shaped or
and occupies whole of the
• only a rim of cytoplasm may be
•Depending upon the size, they are divided into two
•Large lymphocyte: younger cells diameter= 10-12μ
•Small lymphocytes: older cells with a diameter= 7-10μ
•depending upon functions they are further divided
T-lymphocyte- concerned with cellular
B-lymphocytes-concerned with humoral immunity
• These are responsible for development of immunity.
Age: In infants and children, WBC count is more-
In adults it is 4000 to 11000/cumm of blood
Sex: Slightly more in males than in females.
Exercise: Increases slightly
Emotional conditions: Increases slightly
Leucocytosis: occurs in following pathological conditions
Leukopenia: occurs in following pathological conditions
Cirrhosis of liver
Disorders of spleen
Pernicious anaemia 82
Characterized by abnormal and uncontrolled increase.
Increase in WBC’s, above 1000,000/cumm.
Also called blood cancer.
All the WBC’s may not increase at one time.
Leucocytosis occurs because of increase in any one of the
Properties of WBC’s
Diapedesis: property of WBC’s to squeeze through narrow
Ameboid movement: neutrophils, monocytes and
lymphocytes show amebic movement characterized by
protrusion of the cytoplasm and change in shape.
Chemotaxis : Attraction of WBC’s towards the injured
tissues by chemical substances released at the site of injury
Phagocytosis : Neutrophils and Monocytes engulf the
foreign bodies by means of phagocytosis.
Functions of WBC’s
WBC’s generally play an important role in the defense
mechanism of the body.
In the defense mechanism each type of WBC’s act in a
NATURAL KILLER CELLS
•They have large granular cell with independent
•Considered as third type of lymphocyte.
•Kills invading organism or virus and virus infected
cell, malignant cell
•First line of defense against viruses.
PLATELETS.Thrombocytes (platelets) are fragments of
megakaryocytes(red bone marrow)
Cytoplasm is present but do not have a nucleus
Have cell membrane with microtubules below it.
2–3 µm in diameter
Normal range : 150,000 to 400,000 per cmm
Circulation in blood – 8-12 days
•The main function of platelets is the maintenance of
•Repair of ruptured blood vessels
• Clot retraction
•Role in defense mechanism.
Platelets are produced in bone marrow, by budding off
Megakaryocyte and platelet production is regulated by
thrombopoietin, a hormone usually produced by the liver and
Each megakaryocyte produces between 5,000 and 10,000
Reserve platelets are stored in the spleen, and are released
when needed by sympathetically induced splenic contraction.
Old platelets are destroyed by phagocytosis in the spleen
and by Kupffer cells in the liver
These are large tissue cell resembling the
Present in bone marrow and around cutaneous
It do not enter blood circulation
They play important role in producing
hypersensitivity reaction like allergy and
It secretes histamin serotonin and hydrolytic
COMPLETE BLOOD COUNT(CBC)
• The complete blood count, or CBC, lists a number of many
important values. Typically, it includes the following:
• White blood cell count (WBC or leukocyte count)
• WBC differential count
• Red blood cell count (RBC or erythrocyte count)
• Mean corpuscular volume (MCV)
• Mean corpuscular hemoglobin (MCH)
• Mean corpuscular hemoglobin concentration(MCHC)
• Red cell distribution width (RDW)
• Platelet count
• Mean Platelet Volume (MPV
•WBC (white blood cell) (TLC)4,300 and 11,000 cells per cubic
•RBC (red blood cell) ranges between 4.2 to 5.9 million cells per
•Hemoglobin (Hbg) 13 to 18 grams per deciliter (one-hundredth of a
liter) for men and 12 to 16 grams per deciliter for women.
•Hematocrit (Hct) 45%-52% for men and 37%-48% for women.
•Mean corpuscular volume (MCV) ranges between 80 to 100
femtoliters (a fraction of one-millionth of a liter).
•Mean corpuscular hemoglobin (MCH) ranges between 27 to 32
picograms (a small fraction of a gram).
•Mean corpuscular hemoglobin concentration (MCHC) ranges
•Red cell distribution width (RDW) ranges between 11 to 15.
•Platelet count ranges between 150,000 to 400,000 per cmm.
•Mean platelet volume (MPV). The normal range is between 6 to 12