The Blood: Lifeline of the Body - Exploring the Vital Fluid that Sustains Life

The Composition and Function of Blood
THE CIRCULATORY SYSTEM
THE BLOOD
MR. SAGAR PANDYA
ASSISTANT PROFESSOR
M.Sc. Nursing (Child Health Nursing)
Bhagyalaxmi College Of Nursing, Modasa (Guj.)

 Blood is a vital transport system of the body which is continuously
circulating in the vascular system.
 Liquid connective tissue.
 Contains cells suspended in a fluid matrix.
 Blood makes up 6–8% of our total body weight.
 Normal adult blood volume is 5 L.
*Male: 5-6 L
*Female: 4-5 L
 Blood temperature is slightly higher than body temperature.
 Temperature: 38’C (100.4’ F)
 Color: In veins:- Dark red color (Because it has very little oxygen and that
looks almost blue when covered by your skin).
In arteries:- Bright red blood (Because it has a lot of oxygen in it that is
being carried throughout your body to be used by tissues).
 pH: 7.35-7.45
 Viscosity (relative to water): Whole blood:- 4.5-5.5
Plasma:- 2.0
 Osmolarity: 280-300 mOsm/L
THE Blood

Three General functions:-
1. Transportation
 Gases,
 Nutrients,
 Hormones,
 Waste products etc…
2. Regulation
 pH,
 Body temperature,
 Water balance,
 Osmotic pressure etc…
3. Protection
 Prevent blood loss (by clotting)
 Prevent infection etc…
HEMATOLOGY:- It is the branch of medical science that deals
with the study of blood and blood forming tissues.
Blood Functions

COMPOSITION OF BLOOD
Whole blood (8% of body weight)
Blood Plasma (55%)
(Blood-cells=Plasma)
Water Plasma Protein Other solutes
(91.5%) (7%) (1.5%)
- Albumins - Electrolytes
(3.5-5 gm/dl) - Nutrients
- Globulins - Gases
(2-3.5 gm/dl) - Waste products
-Fibrinogen -Regulatory
(0.2-0.3 gm/dl) substances
The Formed Elements
(Cellular material/ Blood cells & Cell
fragments)
(45%)
* Red blood corpuscles(RBC)
(Erythrocytes)
* White blood corpuscles(WBC)
(Leucocytes)
* Platelets (Thrombocytes)

Plasma-55%
Formed
elements-
45%
Buffy
coat-<1%

Blood Plasma
(Blood – cells = Plasma)
 Extracellular matrix (Straw colored clear liquid).
 Makes up 50–60% of blood volume.
 3 components:-*Water (91.5%)
*Plasma proteins (7%): Albumins (55-60%)
Globulins (35-40%)
Fibrinogen (7-8%)
*Other solutes (Nutrients, enzymes,
hormones, gases, waste products,
electrolytes etc…) (1.5%)
PLASMA PROTEINS:
 Confined to bloodstream.
 90% made in liver [Hepatocytes (liver cells) synthesize most
plasma proteins].
 Normal amount:6-8 gm/dl.

Albumins -
- Most abundant plasma protein [about 60% of total
(3.5-5 gm/dl)].
- Smallest Protein.
- Regulates osmotic pressure.
- Transport substances: Act as carrier protein for-
*Fatty acids
*Thyroid hormones
*Steroid hormones etc…
Globulins –
- Large proteins.
- 35-40% of total plasma proteins (2-3.5 gm/dl).
- Also called immunoglobulin (Antibodies).
- Help protect the body from antigens.
- Immunoglobulin (antibodies) bind to foreign substances
called antigens & form antigen-antibody complexes.
- Transport globulins (small molecules):
hormone-binding proteins, Metalloproteins, Lipoproteins,
steroid-binding proteins etc…

Fibrinogens –
- Large proteins.
- 7-8% of total plasma proteins (0.2-0.3 gm/dl).
- Clotting proteins – Help to stem blood loss when a blood
vessel is injured.
- Produce long, insoluble strands of fibrin for clotting.
- Plays essential role in blood clotting.
Functions of plasma proteins:
1. Coagulation of blood – Fibrinogen to fibrin.
2. Defense mechanism of blood – Immunoglobulin's.
3. Transport mechanism – α Albumin, β globulin transport
hormones, gases, enzymes, etc.
4. Maintenance of osmotic pressure in blood.
5. Acid-base balance.

6. Provides viscosity to blood.
7. Provides suspension stability of RBC.
8. Reserve proteins.
OTHER SOLUTES:
Electrolytes:*Sodium(Na+): 135-145 mmol/L.
*Potassium(K+): 3.5-5 mmol/L.
*Chloride(Cl-): 98-107 mmol/L.
* Bicarbonates(HCO3
-): 21-30 mmol/L.
*Ferrous (Fe2+): 67-175 mEq/dl (Male)
50-170 mEq/dl(Female)
*Sulfate: 0.6-1.2 mEq/L
*Magnesium(mg2+): 1.5-1.9 mg/dl.
*Calcium(Ca2+): 8.5-10.5 mg/dl
*Phosphorous: 2.5-4.5 mg/dl

Nutrients:*Glucose 70-110 mg/dl (Fasting)
79–160 mg/dl(Random)
*Amino acid 33-51 mg/dl
*Lactic acid 6-16 mg/dl
* Total lipid: 400-800 mg/dl
*Cholesterol 150-200 mg/dl
*Fatty acids 190-420 mg/dl
*High-density lipoprotein (HDL) 35-60 mg/dl
*Low-density lipoprotein (LDL) 80-150 mg/dl
*Neutral Fats (triglycerides) 50-150 mg/dl
*Phospholipids 8-11 mg/dl
Nitrogenous Wastes:
*Ammonia 15 to 45 µ/dl (11 to 32 µmol/L)
*Urea 7 to 20 mg/dl (2.5 to 7.1 mmol/L)
*Creatinine 0.6 to 1.2 mg/dl (Male)
0.5 to 1.1 mg/dl (Female)

Uric acid 3.4-7.0 mg/dl (Male)
2.4-6.0 mg/dl (Female)
Bilirubin 0.1 to 1.2 mg/dl (1.71 to 20.5 µmol/L)
Direct (Conjugated) bilirubin: 0.1-0.3 mg/dl
Indirect (Unconjugated) bilirubin: 0.2-0.7 mg/dl
Gases: O2,CO2,N2 etc…
Regulatory substances:
Hormones-Regulates growth, metabolism &
development,
Enzymes- Catalyze chemical reactions,
Vitamins- Cofactors for enzymatic reactions

Differences between Plasma and Interstitial
fluid
 Plasma is similar to, and exchanges fluids with, interstitial
fluid.
 Plasma is matrix of formed elements
 Materials plasma and IF exchange across capillary walls:
*Water
*Ions
*Small solutes.
Dissolved proteins: Plasma proteins do not pass through
capillary walls
Ionic Composition of Plasma and Interstitial Fluid Is Similar
(Because the plasma and interstitial fluid are separated only by
highly permeable capillary membranes, their ionic composition
is similar).
 The most important difference between these two
compartments is the higher concentration of protein in the
plasma; because the capillaries have a low permeability to the
plasma proteins, only small amounts of proteins are leaked
into the interstitial spaces in most tissues.

Plasma
Serum
clotting proteins (fibrin)
Serum:
(Plasma – Clotting Proteins = Serum)
An amber-colored, protein-rich liquid which separates out when
blood coagulates (rich of immunoglobulins).

The Formed Elements
(Cellular material/ Blood cells & Cell fragments)
• Red blood cells (R.B.C.)
• White blood cells (W.B.C.)
 Granular leukocytes (Granulocytes)
 Neutrophils
 Eosinophils
 Basophils
 Agranular leukocytes (Agranulocytes)
 Lymphocytes
- T cells, B cells & natural killer (NK)
cells
 Monocytes
• Platelets (special cell fragments)

 Red blood cells- also known as RBCs, red cells, red blood
corpuscles, haematids, erythroid cells or erythrocytes.
 Most abundant cell in the blood.
 Red blood cells (RBCs) make up 99% of blood’s formed elements.
 Formation of RBC called Erythropoiesis - Formed in the bone
marrow (Red Bone Marrow).
 Destruction of RBC is known as Hemolysis.
 RBC having antigens (on the cell membrane) that decides the blood
group of blood.
 Normal RBC counts : 3.5 – 6.5 millions/mm3
Male: 4.5 – 6.5 millions/mm3
Female: 3.5 – 5.5 millions/mm3
Red Blood Cells / Erythrocytes

 Hematocrit/Packed cell volume (PCV): Percentage of RBCs in
whole blood.
Male: 42–52%
Female: 35–47%
 The spleen is known as “Graveyard of RBCs”.
 Life span: 120 days
Variations in Size and numbers of RBCs:
 RBCs counts increases from normal counts (6.5 million/mm3) in whole
blood, than that condition is known as Polycythemia.
 RBCs counts decreases from normal counts (3.5 million/mm3) /
Hemoglobin in whole blood, than that condition is known as Anemia
(A disease condition).
 Decreases size of RBCs – Microcytes.
 Increases size of RBCs – Macrocytes.
 Unequal size of RBCs – Anisocytes.

RBC Anatomy:
External structure
 SHAPE:- Biconcave disc-shaped (This
biconcave shape allows the cells to
flow smoothly through the narrowest
blood vessels like capillaries).
 SIZE:-*6-8 micrometers in diameter
(7.5m)
*2 m thick at its periphery
& 1 m thick at its center.
STRUCTURE:- *Small and highly specialized
disc.
*Thin in middle and thicker at
edge.
Internal structure
 Contain very few organelles.
 Lack a nucleus, nuclear DNA, and most organelles, including the
endoplasmic reticulum and mitochondria.

 Each RBC contains 30 picogram of hemoglobin (A metalloprotein-
coloring pigment).
 The red color of RBC is due to presence of Hemoglobin.
Hemoglobin (Hb)
 Hemoglobin molecules are the most important component of RBCs.
 Hemoglobin (iron protein) is found in the RBC.
 Protein molecule, transports respiratory gases.
 Hemoglobin is a specialized protein that contains a binding site for the
transport of oxygen and other molecules.
 The RBCs’ distinctive red color is due to the spectral properties of the
binding of heme iron ions in hemoglobin.
 Each human red blood cell contains approximately 280 million
hemoglobin molecules.

 Normal amount:- 12-18 gm/dl
MALE: 14-18 gm/dl
FEMALE: 12-16 gm/dl
INFANTS: 18-23 gm/dl
 Hemoglobin carries oxygen from the lungs to the rest of the body
and carbon dioxide binds to the RBC and is taken to the lungs to be
exhaled.
 This protein is responsible for the transport of more than 98% of the
oxygen, while the rest travels as dissolved molecules through the
plasma.
 One Hb molecules can combine with 4 molecules of oxygen.
 When Hb combines with 4 molecules of oxygen, oxyhemoglobin is
formed.
 One gram of pure Hb can combine with 1.39 ml of oxygen when
fully saturated. This is called oxygen carrying capacity of hemoglobin.
 Deoxyhemoglobin- free of oxygen or dark red color.
 Carbon dioxide in the blood binds to the globin part of hemoglobin,
which is called carbamino-hemoglobin.

HEMOGLOBIN STRUCTURE
 A hemoglobin consists of a protein called globin ( 4 subunits
-2  chains and 2  chains) or a ring like non protein pigment called
heme is bound to each of the four chains.
HEME:
Each Heme molecules made up of iron (Fe2+) or Porphyrine rings.
GLOBIN: 4 subunits - 2  chains
2  chains
Each heme (4) molecules bind with each subunits of globin (1) proteins.

Functions of RBCs
* Transport oxygen from lungs to the tissues (oxyhemoglobin).
* Transport carbon-dioxide from tissues to lungs
(carboxyhemoglobin)
* Hemoglobin acts as a buffer and regulates the hydrogen ion
concentration (acid base balance).
* Carry the blood group antigens and Rh factor.
RBCs Life Cycle
 The life span of erythrocytes is about 120 days and their breakdown,
or hemolysis, is carried out by Phygocytic Reticuloendothelial
Cells.
 These cells are found in many tissues but the main sites of hemolysis
are the spleen, bone marrow and liver.
 As erythrocytes age, their cell membranes become more fragile and
so more susceptible to hemolysis.

 1% of circulating RBCs wear out per day (about 3 million RBCs/Sec.).
RBCs after 120 days (RBCs fragile)
Phagocytized by Reticuloendothelial system
(Tissue macrophages- Kupffer cells, Spleen etc…)
Membranes of RBC rupture
(Hemoglobin split)
Heme Globin
Ferrous (Fe2+) Biliverdin (Green) Breakesdown into
(Free Iron) (unconjugated bilirubin) amino acids
Reuse (when requires)

Ferrous (Fe2+) Biliverdin (Green)
(Free Iron) (Unconjugated bilirubin)
Transported from blood Bilirubin (Yellow)
to liver by transferrin (Conjugated bilirubin)
protein (carrier protein)
Store in liver in the form Transported to liver
of ferritin (Fe3+)
Bilirubin is released by liver into bile,
Reuse (when requires) which passes into small intestine & than
into the large intestine (for digestion of food)
In the large intestine, bacteria convert
bilirubin into urobilinogen
(through blood by albumin)

Some urobilinogen absorbed Most urobilinogen is eliminated
Back into the blood, converted in feces in the form of a brown
to a yellow pigment called pigment called stercobilin
Urobilin. (gives feces its characteristic
color).
Blood filter in kidney and urobilin
excreted in urine (yellow color of Excreted out from the body
urine is due to urobilin)
Excreted out from the body

Amino
acids
Reused for
protein synthesis
Globin
Urine
Stercobilin
Bilirubin
Urobilinogen
Feces
Large
intestine
Small
intestine
Circulation for about
120 days
Bacteria
Bilirubin
Red blood cell
death and
phagocytosis
Transferrin
Fe3+
Fe3+ Transferrin
Liver
+
Globin
+
Vitamin B12
+
Erythopoietin
Key:
in blood
in bile
Erythropoiesis in
red bone marrow
Kidney
Macrophage in
spleen, liver, or
red bone marrow
Ferritin
Urobilin
Heme
Biliverdin
Bilirubin
Fe3+
14
13
12
11
10
9
8
7
6
5
4
3
2
1

Some RBCs investigations:
 Erythrocytes Sedimentation Rate (ESR):
Rouleaux Formation: When a freshly drawn drop of blood is
observed under microscope, the RBCs
are seen adhered to each other and arranged like a pile of
coins. This is called Rouleaux Formation.
(It is due to negative charges on RBCs which keep the RBCs
dispersed in plasma or lost when blood is kept outside.)
* Rouleaux formation is influnced
by the plasma proteins, bacterial toxins
and number, size or shape of RBCs.
* Albumin contributes to the negative
charge on RBCs and hence decreases
Rouleaux formation, globulin and
fibrinogen decrease the negative charge
on RBCs and so favor Rouleaux formation.

 By Westergren’s method:
Males: 3-5 mm at the end
of 1st hour
Females: 5-12 mm at the
end of 1st hour
 By Wintrobe’s method:
Males: 0-9 mm at the end
of 1st hour
Females: 0-22 mm at the
end of 1st hour

 Mean Corpuscular (Cell) Volume (MCV):
* It is the mean volume of a single RBC.
PCV X 10
MCV = ---------------------------------
RBC count in million/mm3
* NORMAL MCV = 78-98 fl (Femtolitres)
NOTE: * MCV is increased in macrocytic anemia (Eg: Pernicious Anemia).
* Decreased in microcytic anemia (Eg: Iron Deficiency Anemia).
 Mean Corpuscular (Cell) Hemoglobin (MCH):
* It is the amount of Hb in a single RBC (average amount of
Hb per cell).
Hb in gms/dl X 10
MCH = ---------------------------------
RBC count in million/mm3
* NORMAL MCH = 27-32 pg/cell (Picogram)

NOTE: * MCH is increased in macrocytic anemia (Eg: Pernicious Anemia).
* Decreased in hypochromic anemia (Eg: Iron Deficiency Anemia).
 Mean Corpuscular (Cell) Hemoglobin Concentration
(MCHC):
* It is percentage concentration of Hb in a single RBC and is
expressed in percent..
Hb in gms/dl X 100
MCHC = ---------------------------------
PCV
* NORMAL MCHC = 30-35%
NOTE: * MCHC is normal in Pernicious Anemia.
* Decreased in Iron Deficiency Anemia.

HEMATOPOIESIS / HEMOPOIESIS
 The Process of formation of formed elements / blood cells is called
Hematopoiesis.
 Production/Formation of RBCs – Erythropoiesis
 Production/Formation of WBCs – Leukopoiesis
 Production/Formation of Platelets – Thrombopoiesis
 Origin Of Blood Cells
 Negative feedback systems regulate the total number of RBCs and
platelets in circulation.
 Abundance of WBC types based of response to invading pathogens or
foreign antigens.
 Hemopoiesis or hematopoiesis primary site is Red bone marrow.
 Some WBCs are produced in the lymphatic tissue and bone marrow.

 All cells are differentiated from single cell called stem cell.
(An undifferentiated cell of a multicellular organism which is capable
of giving rise to indefinitely more cells of the same type, and from
which certain other kinds of cell arise by differentiation.)
 Stem cells in bone marrow :- * Reproduce themselves
* Proliferate and differentiate
 Cells enter blood stream through sinusoids.
 Formed elements do not divide once they leave red bone marrow
(Exception is lymphocytes).
 All circulating blood cells originate from a single, most primitive cell
called the Pluripotent Stem Cell (PSC).
 Pluripotent stem cells produce: Committed Stem Cells (CSC)
* Myeloid stem cells: Give rise to red blood cells, platelets,
monocytes, granulocytes (neutrophils,
eosinophils and basophils).
* Lymphoid stem cells: Give rise to lymphocytes (T & B).

 Formation of Colonies of Progenitor cells or Colony Forming
Units (CFU) from the committed stem cells of myeloid series :-
* CFU-E (CFU- Erythrocytes) : Give rise to Erythrocytes.
* CFU-M (CFU- Megakaryocytes) : Give rise to Thrombocytes /Platelets.
* CFU-GM (CFU- Granulocyte macrophage) : Give rise to Granulocytes
(neutrophils, eosinophils and
basophils) or Macrophages.
 Hemopoietic growth factors regulate differentiation and proliferation.
* Erythropoietin – RBCs
* Thrombopoietin – Platelets
* Colony-stimulating factors (CSFs) and interleukins – WBCs

ERYTHROPOIESIS
 The process of formation / production of RBCs is called Erythropoiesis.
 Erythropoiesis occurs in the red bone marrow.
 The process completed in 7 days.
– 5 days for production of RBCs (PSC Reticulocytes)
- 2 days for maturation of RBCs (Reticulocytes Erythrocytes).
 Vitamin B12 & Follic acid (Vitamin B9) is essential for RBC maturation.
 Erythropoiesis is regulated by erythropoietin hormone (glycoprotein)
synthesis or secreted mainly by the kidney (85%) and also by liver
(15%), in response to hypoxemia.
Site of Erythropoiesis
Primitive blood cells first appears in the third week of intrauterine life.
From 3rd week – 3rd month : Yolk Sac (called intravascular
erythropoiesis)
From 3rd month – 5th month : Liver & Spleen (Hepatic
erythropoiesis)

From 5th month (intrauterine life) onwards & in the postnatal
life : The Red Bone Marrow.
Note: * Formation of blood cels occurs in the red bone marrow only
and not in the yellow bone marrow (as it contains fat).
* In infancy all the bone marrow is red, after the age of 20, only
the flat bone and the upper ends (spongy part) of long bones
contain red bone marrow.
Steps of Erythropoiesis (Stages of RBC development)
Pluripotent Haemopoietic Stem Cell
Committed Stem cell of Myeloid series
CFU-E (CFU-Erythrocyte)
Proerythroblast
Early erythroblast

Intermediate erythroblast
Late erythroblast
Reticulocytes
Erythrocytes

 Formation of Proerythroblast from PSC ( CFU-E CSC PSC)
Features: * The cell is large with a big nucleus, which is strongly
basophillic
* Scanty, basophillic cytoplasm
* No Hb
* Mitosis present
 Formation of early erythroblast from proerythroblast
Features: * Smaller than proerythroblast.
* Nucleus, smaller than that of proerythroblast
* Scanty, basophillic cytoplasm
* No Hb
* Mitosis present
 Formation of intermediate erythroblast from early erythroblast
Features: * Smaller than early erythroblast.
* Nucleus, smaller than that of early erythroblast
* Cytoplasm decreased due to start Hb formation
* Mitosis present

Formation of late erythroblast from intermediate erythroblast
Features: * Nucleus very small & deeply stained
* cytoplasm- planty
* Hb present
* No mitosis (i.e. the cell cannot divide further)
 Formation of reticulocyte from late erythroblast
Features: * 8 m diameter
* Nucleus absent
* some DNA is still present which appears as “reticulum”
* Hb present
* No mitosis
 Formation of mature erythrocyte from reticulocyte
Features: * 7.5m diameter
* Nucleus absent
* Hb present
* No mitosis
Factors influencing erythropoiesis : Erythropoietin, Hemopoietic
growth factors, Maturation factors,
Hormones, Destruction of RBCs etc…

LEUKOPOIESIS
 The process of formation / production of WBCs is called Leukopoiesis.
 All leukocytes can be made in red bone marrow from hemocytoblasts.
 Lymphocytes can be made in either red bone marrow or lymphoi
tissues.
 The production of lymphocytes is stimulated by interleukins and
colony stimulating factors (CSFs)
Site of Leukopoiesis
In Intrauterine Life : In mesoderm & migrate into the blood vessels
In The Postnatal Life : * The granulocytes & monocytes develop from
the red bone marrow
* The lymphocytes develop from the lymphoid
tissues mainly

Steps of Leukopoiesis (Stages of WBC development)
Committed Stem cell Committed Stem cell
of Myeloid series of Lymphoid series
CFU-GM (CFU-Granulocyte Lymphoblast
macrophage)
Prolymphocyte
Myeloblast Monoblast Lymphocytes
Promyelocyte Promonocyte
T B
Monocyte Lymphocytes Lymphocytes
Eosinophilic Basophilc Neutrophilic
Myelocyte Myelocyte Myelocyte
Eosinophilic Basophilc Neutrophilic
Band cell Band cell Band cell
Eosinophils Basophils Neutrophils
c
v

THROMBOPOIESIS
 The process of formation / production of platelets is called
Thrombopoiesis.
 All thrombocytes / platelets can be made in red bone marrow from
hemocytoblasts.
 The production of thrombocytes is stimulated by thrombopoietin
secreted and synthesis by kidney & liver.
Site of Thrombopoiesis
From 3rd week – 3rd month : Yolk Sac
From 3rd month – 5th month : Liver & Spleen
From 5th month (intrauterine life) onwards & in the postnatal
life : The Red Bone Marrow.

Steps of Thrombopoiesis
(Stages of Platelets development)
Committed Stem cell of Myeloid series
CFU-M (CFU-Megakaryoblast)
Promegakaryoblast
Megakaryoblast
Megakaryocyte
Platelets

White Blood Cells / Leukocytes
 Also called leukocytes
 Do not contain hemoglobin
 Have nuclei and other organelles, the
shape depends on type of cell
 Largest sized blood cells
 Lowest numbers in the blood
 Formed in the bone marrow and some in
lymph glands
 Primary cells of the immune system
 Fights disease and foreign invaders
 Certain WBCs produce antibodies
 Life span is from 24 hours to several years
 Size is 8-20 micrometers in diameter

Normal WBCs counts (Total
Leukocyte Counts - TLC):
4000-11000/mm3
Types : (Differential Leukocyte
counts - DLC)
* Granular leukocytes
- Neutrophils (50-70%)
- Eosinophils (1-6%)
- Basophils (0-1%)
* Agranular leukocytes
- Lymphocytes (20-40%)
- Monocytes (2-10%)
Abnormal leukocyte levels :
* Leukocytosis : - Above 11,000 leukocytes/ml
- Generally indicates an infection
* Leukopenia : - Abnormally low leukocyte level
- Commonly caused by certain drugs

Basophil
Eosinophil
Neutrophil
Lymphocyte Monocyte

Functions of WBCs:
- Defend against pathogens
- Remove toxins and wastes
- Attack abnormal cells
Granular Leukocytes:
1) Neutrophils
 50%-70% WBCs (Most commonest type cell)
 Also called polymorphonuclear leukocytes
 Multilobed nucleus (2-5 lobes) with fine granules
 Pale cytoplasm granules with:lysosomal enzymes
or bactericides (hydrogen peroxide and superoxide)
 Neutrophils action:
- Very active, first line defense to bacteria infection
- Engulf pathogens
- Digest pathogens
- Release prostaglandins and leukotrienes
- Form pus
 Duration of development: 6-9 days

 Life Span: 6 hours to a few days
 Function: phagocytes bacteria

2) Eosinophils
 1%-6% WBCs
 Also called acidophils
 Nucleus bilobed
 Large brick-red cytoplasmic granules
 Attack large parasites
 Excrete toxic compounds: Nitric oxide, Cytotoxic enzymes etc…
 Eosinophils action:
- Are sensitive to allergens
- Control inflammation with enzymes that counteract
inflammatory effects of neutrophils and mast cells
 Development:6-9 days
 Life Span: 8-12 days
 Function: - Kill parasitic worms
- Destroy antigen-antibody complexes
- Inactivate some inflammatory chemical of allergy

3) Basophils
 0-1% WBCs (Most rarest type cell)
 Lobed nucleus
 Are small & have histamine-containing granules
 Accumulate in damaged tissue
 Basophils action:
- Release histamine: Dilates blood vessels
- Release heparin: Prevents blood clotting
 Development: 3-7 days
 Life Span: A few hours to a few days
 Functions: - Release histamine and other mediators of inflammation
- Contain heparin, an anticoagulant

aGranular Leukocytes:
1) Lymphocytes
 20%-40% WBCs
 Nucleus spherical or indented
 Are larger than RBCs
 Migrate in and out of blood
 Mostly present in connective tissues and lymphatic organs
 Are part of the body’s specific defense system
 3 Classes of Lymphocytes:
* T cells : - Cell-mediated immunity
- Respond to antibodies on foreign tissue (Attack foreign
cells directly)
* B cells : - Humoral immunity
- Differentiate into plasma cells (activated B cells
that secrete antibodies).
- Produce antibodies
* Natural killer (NK) cells : - Detect and destroy abnormal tissue
cells (cancers)

 Development: Days to weeks
 Life Span: Hours to years
 Function : Mount immune response by direct cell attack (T cells) or
via antibodies (B cells)
2) Monocytes
 2%-10% WBCs
 Nucleus U-shaped
 Largest or most active phagocytes white blood cells
 Monocytes take longer to arrive but arrive in larger
numbers and destroy more microbes
 Important in fighting chronic infection
 Enter peripheral tissues and enlarge or differentiate into macrophages
 Monophils action:
- Engulf large particles and pathogens
- Secrete substances that attract immune system cells and
fibroblasts to injured area

 Development: 2-3 days
 Life Span: months
 Function: - Phagocytosis
- Develop into macrophages in tissues

Leukocytes Deployment :
Leukocytes are deployed in
the infected areas outside
blood vessels via 3 steps.
1) Margination:
Margination is the process
in which free-flowing
leukocytes exit the central
blood stream, and initiate
leukocyte and endothelial
cell interactions by close
mechanical contact.
2) Diapedesis:
The movement or passage
of blood cells, especially
white blood cells, through
intact capillary walls into
surrounding body tissue.

3) Chemotaxis:
Gather in large numbers (WBCs) at areas of tissue damage and
infection by following the chemical trail of molecules released by
damaged cells or other leukocytes.
Phagocytosis: Destroy foreign substances, dead cells or microbes.

Platelets / Thrombocytes
 Platelets also called Thrombocytes.
 Formation or production of platelets is
called Thrombopoiesis.
 Formation is regulated by thrombopoietin.
 Platelets are smallest, colorless, non nucleated
blood cell which is responsible for
Hemostasis (cessation of bleeding).
 The cytoplasm contains mitochondria,
granules, contractile elements, tubules etc…
 Platelets are not actually cell, it is small
fragments derived from ruptured
multinucleate cells (megakaryocytes).
 Each fragment enclosed in a piece of plasma
membrane.
 Granules contain blood clot promoting chemicals
like serotonin, Ca2+, enzymes, ADP, and platelet
-derived growth factor (PDGF).

 Size: 2-4 micrometers in diameter
 Shape: - Rounded or wrinkled shape (When inactivated in circulation)
- Irregular shape (When activated at the site of injury)
 Life span: 5-9 days (After that, removed by spleen & liver or 2/3 Of
total platelets are reserved in spleen for emergencies)
 Normal Platelets Counts : 150000-350000/mm3 (1.5-3.5 Lack/mm3)
 Abnormal thrombolytic levels :
* Thrombocytosis > 350000/mm3
* Thrombopenia < 150000/mm3
 Functions : - Blood clotting
- Clot retraction
- Defense mechanism
- Hemostasis
- Repair and rupture of blood vessel
- Vasoconstriction (after vascular injury)
- Store serotonin, histamine etc…

HEMOSTASIS
Hemostasis is the stoppage of bleeding, which is vitally important when
blood vessels are damaged.
Hemostasis involves three phases:
• Vascular spasms
• Platelet plug formation
• Blood coagulation (Blood clotting) Secondary Hemostasis
• Fibrinolysis Tertiary Hemostasis
Primary Hemostasis

Vasoconstriction (Vasospasm)
Platelets comming in contact with exposed collagen (injured blood
vessel) release: serotonin (5-hydroxytrytamine), ADP,
TXA2(Thromboxane), which accelerate vasoconstriction and causes PLT
to swell and become more sticky.
30-minute contraction
Blood vessels damage (Bleeding)
Muscles collagen fiber expose
Platelets contact with exposed collagen
Chemicals released by platelets
(serotonin, ADP, TXA2 etc…)
Smooth muscles contraction increases
Blood vessels contract (Vasospasm)
Blood lose decrease

Platelets Plug Formation
It is the II step of hemostasis which results due to grouping of activated
platelets finally results in temporary cessation of the bleeding
Begins within 15 seconds after injury
Blood vessels damage (Bleeding)
Muscles collagen fiber expose
Platelets contact with exposed collagen
Chemicals released by platelets
(serotonin, ADP, TXA2 etc…)
Platelet adhesion (attachment)
Platelet aggregation (stick together)
forms platelet plug
Bleeding stop temporary

BLOOD COAGULATION / BLOOD CLOTTING:
 Coagulation mechanism includes
cascade of reactions in which some
inactive enzymes (Clotting factors) are
activated and the activated enzymes,
in turn, stimulate other inactive enzymes.
 Clotting – The sequential activation
(reaction cascade) of the clotting factors
finally leads to the formation of fibrin
meshwork.
 Begins 30 seconds or more after the injury.
 Blood usually clots within 3-6 minutes.
 Blood Clot: * Fibrin network
* Covers platelet plug
* Traps blood cells
* Seals off area
 Clotting Factors:
- Also called Procoagulants
- Proteins or ions in plasma
- Required for normal clotting

 Many clotting factors (13) in plasma are involved in clotting.
 These factors are inactive in the blood.
 They are activated when: - Blood vessel is broken, or
- Blood flow slows down.
 Blood cells are trapped in fibrin meshwork to form a hard clot.
 Cascade Reactions : During coagulation phase Chain reactions of
enzymes and proenzymes form 3 pathways
* Extrinsic pathway: - Begins in the vessel wall
- Outside blood stream
* Intrinsic pathway: - Begins with circulating proenzymes within
bloodstream
* Common pathway: - Where intrinsic and extrinsic pathways
converge
 3 Stages of Clotting :
1. Extrinsic or intrinsic pathways lead to formation of
prothrombinase.
2. Prothrombinase converts prothrombin into thrombin.
3. Thrombin converts fibrinogen (soluble) into fibrin (insoluble)
forming the threads of the clot.

The Extrinsic Pathway:
 Activator of the pathway (CF-III / Thromboplastin) is released by the
damaged tissues & than thromboplastin enters into the blood from
outside (tissue) so it is called as Extrinsic pathway.
 Fewer steps then intrinsic and occurs rapidly
When blood comes in contact with injured
tissue – tissue thromboplastin (CF III)
CF III interacts with proconvertin (CF VII),
Proaccelerin (CF V) and Ca2+
(CF VII CF VIIa) or (CF V CF Va)
activating
Stuart factor (CF X CF Xa)
Forms Prothrombinase

The Intrinsic Pathway :
 Stimulator or activator (Hageman factor / CF XII) of the pathway is
present in the blood and does not enter from outside so it is named
as Intrinsic pathway.
 More complex and slower than extrinsic pathway.
When Endothelium cells become roughened or damaged
Blood can come in contact with exposed collagen fibers
activates Hageman factor (CF XII)
(CF XII CF XIIa)
Activated CF XIIa activates plasma enzyme –
plasma thromboplastin antecedent (PTA: CF XI)
(CF XI CF XIa)
CF XIa in the presence of Ca 2+ activates-
Christmas factor (CF IX)
(CF IX CF IXa)

CF IXa interacts with antihemophilic factor (CF VIII),
Ca 2+ to form a complex that
activates Stuart factor (CF X) or Proaccrlerin (CF V)
(CF X CF Xa) or (CF V CF Va)
Forms Prothrombinase
The Common Pathway :
 Coagulation mechanism is composed of an extrinsic and intrinsic
pathway, which eventually merge into one Called common pathway.
 The formation of prothrombinase marks the beginning of the
common pathway
Formation of Prothrombinase
Prothrombinase with Ca2+ catalyzes conversion of
prothrombin (CF II) to thrombin (CF IIa)
(CF II CF IIa)

Thrombin (CF IIa) with Ca2+ converts
soluble fibrinogen (CF I) into insoluble
fibrin (CF Ia)-Loose fibrin threads or
activates Fibrin stabilizing factor (FSF:
CF XIII)
(CF I CF Ia- Loose fibrin threads)
or
(CF XIII CF XIIIa)
CF Ia- Strengthed fibrin threads
(Clot Retraction- Tightening of fibrin
clot)
Permanent stoppage of bleeding
NOTE: Calcium ions (Ca2+) and
vitamin K are both essential to
the clotting process.

Fibrinolysis (Dissolution of clot):
Temporary fibrin clot systematically and gradually dissolved as
the vessel heals.
Key components : - Plasminogen (inactive form)
- Plasminogen activators
- Plasmin
- Fibrin
- Fibrin Degradation Products (FDP)
Activators of Fibrinolysis:
Intrinsic activators: Factor XIIa, XIa, kallikrein
Extrinsic activators: Tissue type plasminogen activator (t-PA)
Urokinase type plasminogen acitvator (u-PA)
Exogenous activators: Streptokinase (derived from beta strep)
Note: * An inactivated plasma enzyme called Plasminogen is
incorporated into the clot.
* Both body tissues and blood contain plasminogen activators
can activate plasminogen to plasmin or fibrinolysin.

Abnormalities of hemostasis
Coagulation Disorders
 Thrombosis is the abnormal clotting of blood in an unbroken vessel.
 Thrombus is a clot that attaches to the wall of blood vessel.
 Embolus is a clot that comes off the wall of blood vessel and travel
in the blood stream.
 Embolism is the blockage of blood flow by an embolus that lodges in
a small blood vessel.
 Infarction refers to cell death that results from embolism. Infarction
is responsible for most strokes and heart attacks.
Bleeding Disorders
 Thrombocytopenia: The number of circulating platelets is deficient
(<150,000/l) causes spontaneous bleeding
from small blood vessels all over the body.
 Deficiency of clotting factors due to impaired liver function.
 Hemophilia: Hereditary bleeding disorders due to deficiency of
clotting factors (V,XIII,IX,X,XI).

ANTICOAGULANTS
Anticoagulants are plasma proteins responsible for preventing blood
clotting
 Although tissue breakdown and platelets destruction are normal
events in the absence of trauma, intravascular clotting does not
usually occur because:
- The amounts of procoagulants released are very small
- Natural anticoagulants are present (Antithrombin III, Heparin,
Antithromboplastin, Protein C and S, fibrin fibers)
Natural anticoagulants :
 Antithrombin III – inhibits factor X and thrombin.
 Heparin from basophils and mast cells potentiates effects of
antithrombin III (together they inhibit IX, X, XI, XII and thrombin).
 Antithromboplastin (inhibits „tissue factors” – tissue thromboplastins).
 Protein C and S – activated by thrombin; degrade factor Va and VIIIa.
 Prostacyclin also inhibits platelet aggregation.

Tests of coagulation
Bleeding time (BT) test –
- It is the time requires for complete cessation of bleeding after its
initiation.
- Time requires for the process of Vasospasm + Platelets plug
formation.
- Normal Time: 3 - 6 Minutes
Clotting time (CT) test –
- It is the time requires for blood to clot after initiation of bleeding.
- Time requires for the process of Vasospasm + Platelets plug
formation + Blood coagulation
- Normal Time: 3 - 8 Minutes
Prothrombin time (PT) test –
- It is the time requires for blood to clot after adding
thromboplastin (CF III) into blood.
- Evaluates extrinsic system (VII, X, V, II, fibrinogen)
- Normal Time: 8 - 12 Sec.

Activated Partial Thromboplastin Time test (aPTT) –
- It is also called Kaolin cephalic clotting time
- It is the time requires for blood to clot after adding kaolin &
silica (artificial CF XII) into blood.
- Evaluates intrinsic system (VIII, IX, XI, XII, X, V, II, fibrinogen)
- Normal Time: 30 - 50 Sec.

BLOOD GROUPS / TYPES
History:
 Karl Landsteiner discovered the ABO Blood Group System in 1900.
 He and his five co-workers began mixing each others red cells and
serum together and inadvertently performed the first forward and
reverse ABO groupings
Landsteiners Rule:
 If an antigen (Ag) is present on a patients red blood cells the
corresponding antibody (Ab) will not be present in the patients
plasma, under ‘normal conditions’.
There are two principles:
 Almost all normal healthy individuals above 3-6 months of age have “
naturally occurring Abs” to the ABO Ags that they lack.
 These Abs naturally occurring because they were stimulated by
antigenic stimulation.
 These “naturally occurring” Abs are mostly IgM class ( or some IgG).

Blood groups – based on presence or absence of various
antigens on the surface of RBC membrane
Blood type is based on the presence of 2 major antigens in RBC
membranes- A and B
Blood type Antigen Antibody
A A anti-B
B B anti-A
A & B AB no anti body
Neither A or B O anti-A and anti-B

Antigens / Agglutinogens :- Glycoprotein on the surface of a RBC
membrane
Antibody / Agglutinins:
- Proteins made by lymphocytes in plasma which are made in response
to the presence of antigens.
- They attack foreign antigens, which result in clumping (agglutination).
Agglutination: - Agglutination is the clumping of particles
(aggregation and lysis of incompatible RBCs).
AntigensandAntibodiesof ABOBloodTypes

There are many Blood groups or types and more than 100 of antigens,
But in human mainly four blood groups (A, B, AB & O) or three of
antigens (A, B & D) is found.
Group A
 Approximately 40% (A+= 34% & A-= 6%)
the population (US) is group A.
 In India 21.37% (A+= 20.8% & A-= 0.57%)
 No B antigens present.
 These individuals form potent anti-B antibodies
which circulate in the blood plasma at all times.
 Group A can donates blood to Group A or Group AB
(A+= A+ & AB+ Or A-= A+, AB+, A- & AB- ).
 Group A can receives blood from Group A or
Group O.
(A+= A+, O+, A- & O- Or A-= A- & O- )

Group B
 Approximately 11% (B+= 9% & B-= 2%) of
the population (US) is group B.
 In India 39.93% (B+= 38.14% & B-= 1.79%).
 No A antigens present.
 These individuals form potent anti-A antibodies
which circulate in the blood plasma at all times.
 Group B can donates blood to Group B or Group AB
(B+= B+ & AB+ Or B-= B+, AB+, B- & AB- ).
 Group B can receives blood From Group B or
Group O.
(B+= B+, O+, B- & O- Or B-= B- & O- )

Group AB
 Approximately 4% (AB+= 3% & AB-= 1%) of
the population (US) is group AB.
 In India 9.42% (AB+= 8.93% & AB-= 0.49%).
 Both A and B antigens present.
 These individuals possess no A or B antibodies.
 Universal recipients (AB+) (neither anti-A or
anti-B antibodies)
 Group AB can donates blood to Only Group AB
(AB+= AB+ Or AB-= AB+ & AB- ).
 Group AB can receives blood From all blood
groups (AB+= Everyone Or AB-= A-, B-, AB-, O-).

Group O
 Approximately 45% (O+= 38% & O-= 7%) of
the population (US) is group AB.
 In India 29.28% (O+= 27.85% & O-= 1.43%).
 No A or B antigens present, think of as
“0” antigens present.
 These individuals form potent anti-A and anti-B
antibodies which circulate in the blood plasma
at all times.
 Universal donor (O- ) (neither A or B
antigens).
 Group O can donates blood to all blood groups
(O+= A+, B+, AB+, O+ & O- = Everyone).
 Group O can receives blood from only Group O (O+= O+ & O- Or
O-= O- ).

Rh (D-Antigen) System
 The Rh, or rhesus, factor was discovered in 1940 by K. Landsteiner
and A. S.Wiener.
 When they observed that an injection of blood from a rhesus monkey
into rabbits caused an antigenic reaction in the serum component of
rabbit blood (see immunity).
 This system was first discovered in Rhesus monkeys and hence the
name.
 Also called D antigen, Rh factor or Rh antigen.
 Rh refers to the presence or absence of the D antigen on the RBC.
 Either Rh positive (Rh factor present) or Rh negative (Rh factor absent).
 The majority of human beings is Rh positive (85%) / Rh negative is
about 15%.
 Only sensitized Rh-
blood has anti-Rh antibodies.
 Normally, blood plasma does not contain anti-RH antibodies.
 Rh+ 85% dominant & Rh- 15% recessive

Rh incompatibility :
When Rh- Individual receives Rh+ blood, there will not be any
immediate reaction. However, the donor’s red cells induce the formation
of anti-D antibodies in the recipient. If he receives a subsequent Rh+
blood transfusion later, the anti-D antibodies immediately destroy the
donor red cells and this is called Rh incompatibility.
Hemolytic disease of the newborn (HDN) /
Erythroblastosis Fetalis –
If blood from Rh+ fetus contacts Rh-mother during birth, anti-Rh
antibodies made and affect is on second Rh+ baby.
A. Child is Rh+ (or mother is Rh-)
B. During pregnancy fetal Rh+ RBCs escape into maternal circulation
C. Mother produces antibodies to Rh (D) antigen
D. Second pregnancy with Rh+ (D) child results in destruction of fetal
RBCs

Rh Factor and Pregnancy: Rh+ mother w/Rh- baby :– No problem
Rh- mother w/Rh+ baby :– Problem
Rh- mother w/Rh- father :– No problem
Rh- mother w/Rh- baby :- No problem

USES OF BLOOD GROUPING:
 Blood transfusion
 To diagnose or to predict Rh incompatibility
 To investigate a case of disputed paternity.
 Medico legal value-for criminal cases
 Organ transplantation
 Susceptibility to certain diseases (Eg: O group people are more prone to
peptic ulcer & A group people are more prone to stomach cancer).

BLOOD TRANSFUSION
Blood transfusion is generally the process of
receiving blood or blood products into one's circulation intravenously.
Transfusions are used for various medical conditions to replace lost
components of the blood.
INDICATIONS:
* Acute blood loss - as in accidents, surgery etc…
* Bleeding disorders – as in hemophilia, purpura etc…
* Disease of blood – as in severe anemia, leukemia etc…
* In Poisoning – as in carbon monoxide Poisoning
* Shock
Before blood transfusion, the following should be done:
* Blood Grouping
* Cross Matching
* Screening for diseases like AIDS, Hepatitis, Malaria, etc…

Hazards of blood transfusion :
Due to mismatched blood transfusion:
 If there is mismatching, the RBCs will be hemolyzed or clumped and
block small blood vessels causes ischemic changes can result in heart
failure and kidney failure.
 Anaphylactic shock, fever and rigor.
Due to causes other than mismatching:
 Circulatory overload – causes pulmonary edema.
 Transmission of diseases like AIDS, Hepatitis-B, Malaria, etc…
 Iron overload – due to repeated blood transfusions.
 If not [properly stored, the transfused blood may contain some
pyrogens, which can produce fever.

BLOOD PRODUCTS
BLOOD PRODUCT
Any therapeutic substance prepared from human blood
WHOLE BLOOD
Un-separated blood collected into an approved container
containing an anticoagulant preservative solution
BLOOD COMPONENT
1. A constituent of blood , separated from whole blood such as
* Red cell concentrate
* Plasma
* Platelet concentrates
2. Plasma or platelets collected by apheresis
3. Cryoprecipitate prepared from fresh frozen plasma

WHOLE BLOOD :
1 UNIT : 350 ml (300 ml blood + 50 ml Anticoagulants)
450 ml (US)
Maximum storage time : 35 days
Storage temperature : 1-6’ C (4’C)
Transfusion time : 2-4 hours
RBCs : In case of Erythrocytopenia
1 UNIT : 250 ml [330 ml (US)]
Maximum storage time : 42 days
Storage temperature : 1-6’ C (4’C)
Transfusion time : 2-4 hours
1UNIT RBCs = * Increases 1gm/dl Hb
* Increases 2-3% Haematocrit value
WBCs : - No normal use
- Use in adoptive immunity
1 UNIT : 400 ml
Transfusion time : 1 hour

PLATELETS : In case of Thrombocytopenia
1 UNIT : 50-70 ml (Increases 5000-10000 cell/mm3)
[15-20 ml (US)]
Maximum storage time : 5-7 days (5 days)
Storage temperature : 22-24’ C (Room Temp.)
Transfusion time : 15-30 Min.
FRESH FROZEN PLASMA [FFP] :
Mainly for clotting factor or plasma decreases in body
1 UNIT : 200-250 ml
Maximum storage time : 1 year
Storage temperature : Below -30’ C
Transfusion time : 15-30 Min.
CRYOPRECIPITATE PLASMA :
Mainly deficiency of CF-VIII or CF-I (Anti-hemophilic or Fibrinogen)
1 UNIT : 15-20 ml
Maximum storage time : 2 years
Storage temperature : -30’ C

COMPLICATIONS :
1. Transfusion Reaction:
S/S : * Itching * Rashes * Chills
* Sweating * Tachycardia * Hypotension
* Dyspnea * Nausea * Vomiting
* Myalgia (Muscles pain) * Restlessness
* Decreases urine output
Nursing Role : - Stop transfusion (immediately)
- Start 0.9% NaCl (NS)
- Inform the physician
2. Fluid overload / over hydration :
S/S : * Hypertension * Bounding pulse (increases stroke volume)
* Neck vein distension * Dyspnea
* Lungs sound (Wheezing sound)
Nursing Role : - Decreases flow rate of blood at minimum level
- Provide upright position
- Inform the physician

4. Septicemia / Bacteraemia (More than 4 hours) :
Prevention : - Blood transfusion completed within 4 hours.
- Use sterile techniques during blood transfusion.
S/S : s/s of infection.
Nursing Role : - Stop transfusion (immediately).
- Inform the physician.
5. Hypocalcaemia : Due to citrate (anticoagulant present in blood)
bind with free calcium causes calcium loss.
6. Hypokalemia : Due to cell destruction.
7. More blood transfusion in any person causes Hepatitis – C.
8. Iron increases (red color urine).

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