this chapter deals with- 1. what is blood 2. components of blood 3. blood clotting process 4. blood clotting factors 5. blood groups

1. BLOOD

2. FUNCTIONS OF
BLOOD
TRANSPORTATION REGULATION PROTECTION
• Respiration • Regulates pH • WBC protects
against disease
by phagocytosis
• Nutrient carrier • Adjusts and
maintains body
temperature
from GIT
• Reservoir for
substances like
water,
• Transportation
of hormones
from endocrine
glands
• Transports
metabolic
wastes
• Maintains water
content of cells
electrolyte etc.
• Performs
haemostasis

3. INTRODUCTION
• The normal pH range of blood is 7.35 to 7.45,which is slightly
alkaline. The venous blood normally has a lower pH than the arterial
blood because of presence of more Carbon dioxide.
pH of blood
• The temperature of the blood is 38°C(100.4°F), about 1°Chogher than
Temperature
oral or rectal body temperature.
• ‘Viscosity’ means thickness or resistance to flow. Blood is about 3-5
times denser & more viscous(thicker) than water & feels slightly
sticky. Viscosity is increased by the presences of blood cells & plasma
proteins. This thickness contributes to normal blood pressure.
Viscosity
• The colour of blood varies with its oxygen content. Arterial blood is
bright red due to it’s high level of oxygen. Venous blood has given up
much of it’s oxygen in tissues & thus has a darker, dull red colour.
Colour
• Blood constitutes about 20% of extracellular fluid, amounting to 8%
of total body mass. The blood volume is 5L to 6L(1.5gal) in average
sized adult male & 4L to 5L(1.2gal) in an average sized adult female.
Amount

4. COMPOSITION OF BLOOD

5. PLASMA
When formed elements are removed from blood, a straw coloured liquid
called blood plasma is left. The table below describes the chemical
composition of blood plasma-
Liquid portion of blood. Acts as solvent and suspending medium for
WATER(91.5%) components of blood; absorbs, transports and releases heat.
PLASMA
PROTEIN(7.0%)
Exert colloid osmotic pressure , which helps maintain water balance
between blood and tissues and regulates blood volume.
Smallest and most numerous blood plasma proteins; produces by
liver. Transports proteins for several steroid hormones and for fatty
acids.
ALBUMIN
60% of total
Produces by liver and plasma cells, which develop from B lymphocytes.
Antibodies(immuno-globulins) help attack viruses and bacteria. Alpha
and beta globulins transport iron, lipids and fat soluble vitamin.
GLOBULINS
Clotting factors
They are responsible for blood clotting.Produces by liver. Plays essential
role in blood clotting.

6. Inorganic salts.
OTHER SOLUTES(1.5%)
ELECTROLYTES
-
4 4
Help maintain osmotic pressure and plays essential roles in function of
cells, like muscle contraction(Ca), transmission of nerve impulses(Na
and Ca) and maintain acid base balance (phosphate Po)
Products of digestion pass into blood for distribution to all body
cells. Includes amino acids(from proteins), glucose(from
carbohydrates), fatty acids and glycerol(from triglycerides),
vitamins and minerals.
NUTRIENTS
GASES
Oxygen, Carbon dioxide and Nitrogen. More O is associated with
2
hemoglobin inside red blood cells; more CO is dissolved in
2
plasma. N is present but has no known functions in the body.
2
Enzymes, produces by body cells, catalyze chemical reactions.
Hormones, produced by endocrine glands, regulate metabolism,
growth and development. Vitamins are cofactors for enzymatic
reactions.
REGULATORY
SUBSTANCES
Most are breakdown products of protein metabolism and are
carried by blood to organs of excretion. Include urea, uric acid,
creatine, creatinine, bilirubin and ammonia.
WASTE PRODUCTS

7. RBC
• Shape: Biconcave
• Size: 7.2um in diameter
• Thickness: 2um at the periphery and 1um at the center
• Volume: 87um3

8. • Advantages of Biconcave Shape of RBCs:
• Greater surface area for exchange of gases.
• Flexibility of RBC
• Minimal tension when the volume of cell
alters. How is the shape maintained?
 Spectrin
- a contractile protein
- maintains shape and flexibility of RBC
- Antigen on cell membrane – helps in blood group
classification

9. • Adults males: 4.5 – 6 million cu mm of blood
• Adult females: 4 – 5.5 million cu mm of blood
• At birth: 6.7 million cu mm of blood

10. • 62.5% water
• 35% Hemoglobin
• 2.5% :
- Sugar – glucose
- Lipids – Cephalin, Cholesterol & Lecithin
-Protein – Glutathion : insoluble protein which acts
as a reducing agent and prevents damage of
hemoglobin
- Enzymes – Carbonic anhydrase and catalase
- Ions – Na+, K+, Ca2+, PO4
3-

11. • FUNCTIONS
• Respiratory
• Acid Base balance
• Maintain viscosity
• Pigment: various pigments are derived from
hemoglobin after disintegration of RBC.

12. • VARIATIONS
• Physiologic causes of increase count:
• Age
• Gender
• High altitude
• Exercise
• Temperature
• Meal
• Decrease in count: High barometric pressure, Pregnancy, sleep
• Pathological variations:
• Increase: Polycythemia
• Decrease: Anemia

13. • Lifespan – 120 days
• Site of destruction: Reticulo-
endothelial system

14. ERYTHROPOIESIS
• The process of origin,
development and maturation
of erythrocytes.
 Site of erythropoiesis:
 Produced in red bone marrow
 They pass several stages of development before entering into
blood. The process of development of RBC from stem cells takes
about 7 days known as erythropoiesis

15. • Factors necessary for erythropoiesis:
1. General factors:
-Erythropoietin
-Thyroxine
-Vitamins
2. Maturation factors:
-Vitamin B12 (Cyanocobalamin)
-Intrinsic factor of Castle
-Folic acid

16. HEMOGLOBIN
• Hb is the iron containing coloring pigment of RBC.
• 95% dry weight of RBC; 30 – 34% wet weight.
• Molecular weight of Hb is 68,000
• Normal value:
-At birth: 25g/dl
-From puberty: 14-16 g/dl
-Adult males: 15g/dl
-Adult females: 14.5g/dl

17. STRUCTURE OF
HEMOGLOBIN
• Conjugated protein
• Protein part called Globin and iron containing pigment called
heme.
• Heme part is called porphyrin
and is formed by 4 pyrole rings
• Globin is made up of 4
polypeptide chains – 2 alpha and
2 beta chains.

18. Types of Hemoglobin:
• Normal: - Adult Hb
- Fetal Hb
• Abnormal derivatives:
-Carboxyhemoglobin
-Methemoglobin
-Sulfhemoglobin

19. • Each hemoglobin molecule contain four globin chains and four heam
units each with one atom of iron. As each atom of iron can combine
with an oxygen molecules this means that a single hemoglobin
molecule can carry up to four molecule of oxygen.
• An average RBC carries about 280 millions of hemoglobin molecules,
giving each cell oxygen carrying capacity of over a billion oxygen
molecules.
• Iron is carried in the blood stream bound to its transport protein
transferrin and stored in liver.

20. OXYGEN TRANSPORT
• When all sites on hemoglobin molecules is full known as saturated.
Hemoglobin molecule bind with oxygen to form oxyhemoglobin.
• As the oxygen content of blood increases its colour changes too.
• Blood high in oxygen is bright red where as dark bluish represent low
level of oxygen.
• Oxyhemoglobin release its oxygen readily, under conditions
• Low PH:- metabolically active tissues eg:- exercising muscles release
acid waste products and so as local ph falls. Under these conditions
oxyhemoglobin breaks down giving up additional oxygen for tissue use.
• Hypoxia:-
• Temperature:-actively metabolizing tissues which have higher than
normal oxygen needs are warmer than less active ones, increasing
oxygen dissociation.

21. CONTROL OF ERTHROPOIESIS
•
• -ve
•
TISSUE HYPOXIA
KIDNEY SECRETE ERTHROPOITEIN INTO BLOOD
BONE MARROW INCREASES ERTHROPOESIS
RBC NUMBER RISES
INCREASES OXYGEN CARRYING CAPACITY
REVERSES HYPOXIA

22. DESTRUCTION OF ERTHROCYTES
• Hemolysis is carried out by phagocytic reticuloendothelial cells.
• These cells are found in many tissues main sites of hemolysis are the spleen, bone
marrow and liver. As the RBC ages they are more fragile and more susceptible to
hemolysis.
• Iron released by hemolysis is retained in the body and reused in the bone marrow to
form new hemoglobin molecule.
• Biliverdin is formed from the heam part which is reduced to yellow pigment
bilirubin before being bound to plasma globulin and transported to liver and in the
liver it is changed from a fat soluble to a water soluble form to be excreted as a
constituents of bile

23. ERYTHROCYTE SEDIMENTATION
RATE
• Red cells have the property of Rouleaux (piling one on the other)
formation.
• Piled red cells are heavier than the individual ones.
• The rate at which the red cells fall is known as ESR.
• Normal values:
Wintrobe’s method: Males: 0 – 9mm/hr
Females: 0 – 20mm/hr
Westergren’s method: Males: 3 – 7mm/hr
Females: 5 – 9 mm/hr

24. Westergren’s method:
• Westergren’s tube is used which is 300 mm long & opened at
both the ends.
• It requires collecting 2 ml of venous blood into a tube
containing 0 .5 ml of sodium citrate. It should be stored no
longer than 2 hours at room temperature
or 6 hours at 4 °C. The blood is drawn into
the tube to the 200 mm mark. The tube is
placed in a rack in a strictly vertical position
for 1 hour at room temperature,

25. Wintrobe’s method:
• The Wintrobe method is performed similarly except that the
Wintrobe tube is smaller in diameter than the Westergren tube
and only 100 mm long.
• EDTA anticoagulated blood without extra diluent
is drawn into the tube, and the rate of fall of red
blood cells is measured in millimeters after 1 hour.

26. PACKEDCELL VOLUME
• Hematocrit is the fractional volume of blood that the
erythrocytes occupy
• It is a reliable index of red cell population.
• Normal values : Males – 46%
Females – 42%

27. RBCINDICES
• MCV (MEAN CORPUSCULAR VOLUME)
– The average volume of single RBC
PCV per 100ml blood
MCV =  10um3
RBC count (million/cu mm)
Normal range : 78 – 94 um3
 RBC with normal volume are called Normocytes
 RBC with less then normal volume, Microcytes
 RBC with more than normal volume, Macrocytes

28. • MCH (mean corpuscular hemoglobin)
– The average content of Hb in average RBC.
Hb in gm%
MCH =  10pg
RBC count (million/cu mm)
• Normal range: 28 – 32pg

29. • MCHC (mean corpuscular hemoglobin concentration)
– Express the average concentration of hemoglobin per unit
volume of RBC.
– It defined as the ratio of the weight of hemoglobin to
volume of RBC.
Hb in gm%
MCHC =  100
PCV per 100ml blood
Normal range: 33 – 38 gm/100ml of cells

30. FORMED ELEMENTS
NAME AND
APPEARANCE
NUMBER CHARACTERSTICS* FUNCTIONS
Red Blood
Cells(RBCs) or
Erythrocytes
Hemoglobin within RBCs
transports most of the
oxygen and part of
carbon dioxide in the
blood.
4.8 million/µL in
females
4.5 million/µL in without nuclei; live for
7-8 µm diameter,
biconcave discs,
males about 120 days.
Most live for a few
hours to a few days.
Some called T and B other foreign substances
memory cells can live
for many years.
White Blood
Cells(WBCs) or
Leukocytes
Combat pathogen and
5000-10,000/µL
that enter the body.
Phagocytosis.
Destruction of bacteria
with lysozymes,
defensins and strong
oxidants, such as
superoxide anion,
hydrogen peroxide, and
hypochlorite anion.
10-12µm diameter;
nucleus has 2-5 lobes
connected by thin
strands of chromatin;
cytoplasm has very
fine, pale, lilac
Granular
Leukocytes
60%-70% of all
WBCs
Neutrophiles
granules.
*Colors are those seen using Wright’s stain

31. 10-12µm diameter; Eliminates parasites, such as
nucleus usually has 2 lobes worms which are too big to be
2-4% of all connected by s thick strand phagocytosed; phagocytes
antigen-antibody complexes &
combat the effects of
Eosinophils
Basophils
WBCs of chromatin; large, red-
orange granules fill the
cytoplasm. histamine in allergic reactions
8-10µm diameter; nucleus
has 2 lobes; large
Liberate heparin, histamine
and serotonin in allergic
reactions that intensify the
0.5-1% of all
WBCs cytoplasmic granules
appear deep blue-purple. overall inflammatory response.
Medium immune response,
Small lymphocytes are 6-
9µm in diameter; large
lymphocytes are 10-14µm
in diameter; nucleus is
including antigen-antibody
reactions. B cells develop into
plasma cells, which secrete
antibodies, T cells attack
Agranular
Leukocytes
Lymphocytes
(T cells, B
cells &
natural killer
cells)
20-25% of all round or slightly indented; invading viruses, cancer cells,
WBCs cytoplasm forms a rim
around the nucleus that
looks sky blue; the larger
the cell, the more
and transplanted tissue cells.
Natural killer calls attach a
wide variety of infectious
microbes and certain
spontaneously arising tumor
cells.
cytoplasm is visible.

32. Acts on the
hypothalamus, causing
the rise in body
12-20µm
diameter; nucleus
is kidney shaped
or horseshoe
shaped.
temperature with
microbial infections;
stimulates the production
3-8% of all
WBCs
Monocytes
Cytoplasm is blue- of some globulins by the
grey and has
foamy
appearance.
liver; enhances the
production of activated T-
lymphocytes;
Phagocytosis
2-3µm diameter
cell fragments
that live for 5-
9days; contains
many vesicles but
no nucleus.
Form platelet plug in
homeostasis; release
chemicals that promote
vascular spasm and blood
clotting.
150,000-
400,000/µL
Platelets(Thrombocytes)

33. Haemopoiesis: Stages in the development of
blood cells

34. BLOOD GROUPS

37. The Rh blood group system is one of the most polymorphic and antigenic
blood group systems. It is second only to ABO in importance in blood
transfusion and is well known as a primary cause of hemolytic disease of the
fetus and newborn (HDFN). The principal antigen is D, and the terms Rh
positive and Rh negative refer to the presence or absence of D antigen

40. White blood cells
• Also called as leucocytes
• They are colorless
• Much larger than red
blood cells
• One cubic millimeter of
blood contains 7000 to
8000 WBC
• Formed in bone marrow
• Their life span depends on the body need so they
have life span of months or even years

41. Types of WBC
• Granulocytes
These WBC have granules in their cytoplasm.
-Granulocytes include neutrophils, eosinophils
and basophils.
• Agranulocytes
These are without granules in their cytoplasm
-These include monocytes and lymphocytes.

42. Haemopoiesis: Stages in the development of
blood cells

43. NEUTROPHILS
• Neutrophils these small and fast active
scavengers protect the body against bacterial
invasion and remove dead cells and debris
from damaged cells. The average neutrophils
lives 6-9 hrs in blood stream.
(also known as neutrocytes or heterophils) are
the most abundant type of granulocytes and
make up 40% to 70% of all white blood cells in
humans.

45. • A Fc receptor is a protein found on the surface of certain cells –
including, among others, B lymphocytes, follicular
dendritic cells, natural killer cells, macrophages, neutrophils,
eosinophils, basophils, human platelets, and mast cells – that
contribute to the protective functions of the immune system.
• The complement system, also known as complement cascade, is a
part of the immune system that enhances (complements) the
ability of antibodies and phagocytic cells to clear microbes and
damaged cells from an organism, promote inflammation, and
attack the pathogen's cell membrane.

46. • A complement receptor is a membrane-
bound receptor belonging to the complement
system, which is part of the innate immune
system. Complement receptors bind effector
protein fragments that are produced in
response to antigen-antibody
complex. Complement receptor activation
contributes to the regulation
of inflammation, and phagocytosis

47. • Neutrophils are a type of phagocyte and are normally found in
the bloodstream. They are attracted in large number to any area of
infection by chemical substances called chemotaxins, which are
released by damaged cells.
• They are highly mobile and squeeze through capillary walls in
affected area by diapedesis. They engulf and kill bacteria by
phagocytosis. Pus that form in infected area consists of dead tissue
cells, dead and live mirobes and phagocytes killed by microbes.

48. EOSINOPHILS
• Are capable of phagocytosis, are less active
than neutrophils.
• They have specialized role in elimination of
parasites such as worms, which are big to
phagocytosed, in their granules certain toxic
chemical, stored in their granules, which is
released when bind to infecting organism.

49. Eosinophil are often found at the sites of
allergic inflammation such as asthmatic
airway and skin allergies. They promote
inflammation by releasing chemical and
may also dumpen down the inflammatory
process through the release of other
chemical, such as an enzyme that breaks
down histamine

50. BASOPHILS
• Closely associated with allergic reaction,
contain cytoplasmic granules packed with
heparin (anticoagulant), histamine
(inflammatory agent) and other inflammatory
substances. Allergen is stimulus that cause
release of basophils.

51. AGRAUNOCYTES
MONOCYTES
• These are the largest of the white blood cells .
Some are highly motile and phagocytic while
others migrate into the tissues where they
develops into macrophages. Both cells produce
interleukin 1 which is responsible for
inflammation and promotion of fever and sepsis.
• Acts on the hypothalamus, causing the rise in
body temperature associated with microbial
infections.

52. • Stimulate the production of some globulin by
the liver
• Enhance the production of activated T-
lymphocytes.
• Macrophages have important functions in
inflammation and immunity

53. Monocyte- macrophage system
• This is known as reticuloendothelial system, consist of both
monocyte and macrophages. Some macrophages are mobile
where as others are fixed, providing effective defense at key
body location. Fixed macrophages in
• Synovial cells in joints
• Langerhans cells in skin
• Microglial cells in brain
• Hepatic macrophages( kupffer cells) in liver
• Alveolar macrophages in lungs
• Sinus lining macrophages in the spleen, lymph nodes and
thymus gland.
• Mesangial cells in nephron in the kidney
• Osteoclasts in bone.

54. LYMPHOCYTES
• Smaller than monocyte and have large nuclei, they
circulate in blood and are present in great number in
lymphatic tissue such as lymph nodes and the spleen.
Example of antigens includes;-
• Cells that have been invaded by viruses, cancer cells
• Pollen from flower and plants
• Fungi
• Bacteria
• Some large molecule drugs eg- penicillin and aspirin

55. • All the lymphocytes originates from stem
cells, when they are activated in lymphatic
tissue, two different types of lymphocytes are
produced ie B- Lymphocytes and T-
Lymphocytes

56. PLATELETS (THROMBOCYTES)
• These are small non nucleated discs.
• 2 to 4 um in diameter
• Derived from megakaryocytes in the red bone
marrow.
• They contain substances that promote blood
clotting which causes haemostasis (cessation of
bleeding).
• Normal count is 50,000 to 400,000 platelets per
microliter (mcL) or 150 to 400 × 109/L.

57. • The kidney release thrmbopoietin, which
stimulates platelet synthesis.
• Life span is 8 to 11 days
• About a third of platelets are stored in spleen
rather than in circulation, this is an emergency
store that can be released as required to control
excessive bleeding.

58. HAEMOSTASIS
• When blood vessel is damaged, loss of blood
is stopped and healing occurs in a series of
overlapping processes, in which platelets play
a vital part.
• The more badly the vessel damaged , faster the
coagulation begins, sometimes as quickly as
15 seconds after injury.

59. 1. VASOCONSTRICTION
• When platelets come into contact with a damaged
blood vessel, their surface becomes sticky and
adhere to damaged wall and release serotonin(5-
hydroxytrytamine), which constricts the vessel,
reducing blood flow through it. Other chemicals
that cause vasoconstriction eg- thromboxane, are
released by damaged vessels itself

60. 2.PLATELET PLUG FORMATION
• The adherent platelets clump to each other and release
other substances, including ADP, which attracts more
platelets to site.
• Passing platelets sticks to those already at the damaged
vessel and they too release their chemicals.
• This is a positive feedback system by which many
platelets rapidly arrive at the sites of vascular damage and
form a temporary seal the platelet plug.
• It completed after injury in 6 minutes.

61. 3.COAGULATION
• Clotting factors activate each other in a specific
order , resulting in activation of prothrombin
activator eventually which is first step of final
common pathway.
• Prothrombin activate the enzyme thrombin which
convert inactive fibrinogen to insoluble fibrin.
• As clotting proceeds the platelet plug is
progressively stablisied by increasing amount of
fibrin laid down in a three dimensional meshwork
within it.

62. • The maturing blood clot traps blood cells and is
much stronger than the rapidly formed platelet
plug.
• The final common pathway can be initiated by
two processes which often occur together:-
• The extrinsic pathway is activated rapidly within
seconds following tissue damage. Damaged tissue
release a complex of chemicals called
thromboplastin or tissue factor, which initiate
coagulation.

63. • The intrinsic pathway is slower (3-6 min) and is
triggered when blood comes into contact with
damaged blood vessel lining (endothelial).
• After a time the clot shrinks because the platelet
contract, squeezing the serum out, a clear sticky
fluid that consist of plasma from which clotting
factors have been removed.
• Clot shrinkage pulls the edge of the damaged
vessel together, reducing blood loss and closing
off the hole in the vessel wall.

66. 4. FIBRINOLYSIS
• After the clot has formed the process of removing it
and healing the damaged vessel begins.
• The breakdown of the clot or fibrinolysis is the first
stage.
• An inactive substance, plasminogen is present in the
clot is converted to the enzyme plasmin by activators
released from the damaged endothelial cells.
• Plasmin initiate the breakdown of fibrin to soluble
products that are treated as waste material and
removed by phagocytosis.
• As the clot is removed, the healing process restore
the integrity of the vessel wall.

67. Activators
Plasminogen
Plasmin
Fibrin
Breakdown products

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