Blood is composed of plasma and blood cells. Plasma contains proteins, nutrients, waste products, hormones and gases. The three types of blood cells are red blood cells, which contain hemoglobin and carry oxygen; platelets, which help form blood clots; and white blood cells, which protect the body from infection. Blood transports nutrients, gases, hormones, enzymes and waste products around the body, regulates pH and temperature, and protects the body via clotting and immune responses.

1. EMANI APARNA
ASST. PROFESSOR
SRINIVAS COLLEGE OF PHARMACY

2.  Blood is connective tissue composed of liquid
matrix called as blood plasma which dissolves
and suspends various cell fragments.
 It provides a means communication between
the cells of different parts of the body and
the external environment.

3.  Blood is composed of straw-coloured transparent
fluid, plasma in which different types of cells
are suspended.
 Plasma constitutes about 55% and cells about
45% of blood volume.
PLASMA:
 Plasma proteins
 Inorganic salts
 Nutrients, principally from digested foods.
 Organic waste materials.
 Hormones
 Enzymes
 gases

4.  Which makes up 7% of plasma.
 They are largely responsible for creating
osmotic pressure of blood.
 If plasma proteins levels fall, because of
either reduced production or loss from blood
vessels, osmotic pressure is also reduced and
the fluid moves into the tissues (oedema)
and body cavities.

5.  Cell formation
 Contraction of muscles
 Transmission of nerve impulses
 Formation of secretions
 Maintainance of balance between acids and
alkalis.
 Blood is slightly alkaline
 Ph of blood between 7.35-7.45

6.  Food is digested in the alimentary tract and
the resultant nutrients are absorbed.
 Eg: Monosaccharides, amino acids, fatty
acids, glycerol and vitamins.
 Together with minerals they are all required
by all the body cells to provide energy, heat,
materials for repair and replacement and
synthesis of other blood components and
body secretions.

7.  Urea, creatinine and uric acid are the waste
products of protein metabolism.
 They are formed in the liver and conveyed in
blood to the kidneys for excretion.
 Carbon dioxide released by all cells is
conveyed to the lungs for exhalation.

8.  These are chemical compounds synthesized
by endocrine glands.
 Hormones pass directly from the cells of the
glands into the blood which transports them
to target tissues and organs elsewhere in the
body, where they influence cellular activity.

9.  Oxygen, carbon dioxide and nitrogen are
transported round the body in plasma.
 Oxygen and carbon dioxide are also
transported in combination with hemoglobin
in red blood cells.
 Oxygen is carried in combination with
hemoglobin and most carbon dioxide a
bicarbonate ions dissolved in plasma.

10.  Transportation
 Regulation
 Protection

11. There are three types blood cells:
 Erythrocytes or red blood cells
 Thrombocytes or platelets
 Leukocytes or white blood cells

12.  Red blood cells contain oxygen-carrying
protein haemoglobin, which is a pigment that
gives whole blood its red colour.
 A healthy adult male is about 5.4 million RBC
per microliter of blood.
 A healthy adult female is about 4.8 million
per microliter of blood.

13.  Biconcave discs with a diameter of 7-8μm.
 Plasma membrane is both strong and flexible which allows
them to deform without rupturing as they squeeze through
capillaries.
 RBC s lack nucleus and other organelles and can neither
produce nor carry on extensive metabolic activities.

14.  A haemoglobin molecule consists of four molecules of globin
protien joined to four pigmented iron-containing complex called
haem.
 Each haem molecule contains four iron ions each of which can
combine reversibly with four oxygen molecule.
 In the lungs due to the high partial pressure of oxygen, Hb takes
up oxygen and changes to bright red oxyhaemoglobin which is
transported to other body tissues.

15.  Erythropoiesis , the production of RBC’s
starts in the red bone marrow with a
precursor called a proerthroblast.
 The proerythroblast divides several times
producing cells that begin to synthesize
hemoglobin.
 Ultimately a cell near the end of the
development sequence ejects its nucleus and
becomes a reticulocyte.
 Loss of nucleus causes the center of the cell
to indent, producing a distinctive bioconcave
shape.

16.  Reticulocytes retain some mitochondria,
ribosomes and endoplasmic reticulum.
 They pass from red bone marrow into the
bloodstream by squeezing between the
endothelial cells of blood capillaries.
 Reticulocytes develop into mature red blood
cells,within 1 to 2 days after their release
from red bone marrow.

17. GRANULOCYTES (Polymorphonuclear
leukocytes)
GRANULOCYTES
- neutrophils, eosinophils and basophils
AGRANULOCYTES
- Monocytes and lymphocytes

19.  Protect against any foreign materials that
gains entry to the body, mainly microbes,
and to remove waste materials. Eg: cell
debris.
 They are attracted in large numbers to any
area of infection by chemical substances
released by damaged cells, called
chemotaxins.
 They undergo phagocytosis.

20.  Capable of phagocytosis
 Elimination of parasites such as worms
 Major site for allergic reactions.

21.  Basophils are associated with allergic
reactions contain cytoplasmic granules
packed with heparin, histamine and other
substances that promote inflammation.
 Usually the stimulus that causes basophils to
release the contents of their granules is an
allergen.

22. MONOCYTES
 These are the large mononuclear cells that
originate in red bone marrow. Some circulate
in the blood and are actively motile and
phagocytic while others migrate into the
tissues where they develop into
macrophages.
 Monocytes carry out phagocytosis and are
also called macrophages.

23. LYMPHOCYTES
 They are smallest leukocytes .
 They circulate in blood and are present
mainly in lymphatic tissues such as lymph
nodes and spleen.
 They play a crucial role in the immune
response of the body
 Production of antibodies

24. PLATELETS
 Each fragment enclosed by a piece of the
plasma membrane is platelet.
 Platelets break off from the megakaryocytes
in red bone marrow and then enter the blood
circulation.
 They are disc-shaped,2-4μm in diameter and
have many vesicles but no nucleus.
 Platelets help stop blood loss from damaged
blood vessels by forming platelet plug.

25.  Their granules also contain chemicals that
once released, promote blood clotting.
 Platelets have short life span 5-9 days.

26.  Hemostatsis is a sequence of responses that
stops bleeding.
 When blood vessels are damaged or ruptured
the hemostatic response must be quick,
localised to the region of damage.
 Three mechanisms:
1. Vascular spasm
2. Platelet plug formation
3. Blood clotting

27. VASCULAR SPASM.
When arteries or arterioles are damaged the
circularly arranged smooth muscle in their
walls contracts immediately. Such a vascular
spasm reduces blood loss for several minutes
to several hours during which the time the
other hemostatic mechanism go into
operation.

29. PLATELET PLUG FORMATION:
1. Platelets contact and stick to parts of a
damaged blood vessel, such as collagen fibers
of connective tissue underlying the damaged
endothelial cells. This process is called platelet
adhesion.
2. Due to the adhesion, the platelets become
activated, and their characteristics change
dramatically. They extend many projections
that enable them to contact and interact with
one another and they begin to liberate the
contents of their vesicles. Liberated ADP and
thrombaxane A2 play a major role inactivating
the platelets. This phase is called platelet
release reaction.

30. 3. The release of ADP makes them platelets in the
area sticky, and the stickiness of the newly
recruited and activated platelets causes them
to adhere to the originally activated platelets.
This gathering of platelets is called platelet
aggregation. Eventually the accumulation and
attachment of large numbers of platelets form
a mass called platelet plug.
A platelet plug is very effective in preventing
blood loss in a small vessel. Although initially
the platelet plug is loose, it becomes quite
tight when reinforced by fibrin threads formed
during clotting. A platelet plug can stop blood
loss completely if the hole in a blood vessel is
not too large.

31.  When blood is shed out or collected in a
container, it looses its fluidity & becomes a
jelly like mass after few minutes. This
process is called coagulation or clotting of
blood. The clot is a mesh of thin fibrils
entangling the blood cells. These fibrils
consist of fibrin. The fibrin is formed from
fibrinogen.

32.  Coagulation of blood occurs through a series
of reactions due to the activation of a
variety of substances. Those substances
necessary for clotting are called clotting
factors. The clotting factors are

33.  Factor I : Fibrinogen
 Factor II : Prothrombin
 Factor III: Thromboplastin
 Factor IV: Calcium
 Factor V: Labile factor(Proaccelerin or
accelerator globulin)
 Factor VII: Stable factor
 Factor VIII: Antihemophilic factor
 Factor IX: Christmas factor
 Factor X: Stuart–Prower factor
 Factor XI: Plasma thromboplastin antecedent
 Factor XII: Hegman factor
 Factor XIII: Fibrin stabilizing factor

34. Normally during circulation, the blood does not
clot, because the enzymes involved in clotting are
in inactive form. Slight initial activation causes
clotting in which each enzyme activates another
one in a sequential manner till the conversion of
fibrinogen into fibrin. In general, clotting occurs in

35.  Formation of prothrombin activator.
 Conversion of prothrombin into thrombin.
 Conversion of fibrinogen into fibrin.
During the process of blood clotting, the
clotting factors, which are in inactive forms,
are converted into active forms. And their
enzymatic actions produce the successive
reactions one after another in a cascading
manner.
Thus, the various reactions involved in blood
clotting are explained by Enzyme cascade
theory.

36. Prothrombin activator is formed in two ways namely:
1. Extrinsic pathway: In this, the formation of
prothrombin activator is initiated by the tissue
thromboplastin.
2. Intrinsic pathway: In this, the formation of
prothrombin activator is initiated by platelets,
which are within the blood itself.

37. Prothrombin activator converts Prothrombin into
Thrombin in the presence of Calcium. Thrombin itself
can accelerate this reaction by positive feedback
mechanism. That is, the initial Thrombin activates
Factor V. This in turn accelerates the formation of both
Extrinsic & Intrinsic Prothrombin activator.

38. During this, the soluble Fibrinogen is converted
into insoluble Fibrin by Thrombin. Initially, the
fibrinogen is converted into activated fibrinogen,
which is called fibrin monomer. This polymerizes
with other monomer molecules to form Fibrin.
The first formed fibrin contains loosely
arranged strands. This is modified later into a
dense tight aggregate by fibrin stabilizing factor
(Factor XII) & this reaction requires the presence
of calcium ions.