Leukocytes or WBCs are the mobile units of the body’s immune defense system. Immunity is the body’s ability to resist or eliminate potentially harmful foreign materials or abnormal cells. WBC count: 5000 to 11000/ul of blood GRANULOCYTES Polymorphonuclear neutrophils 60-70% Polymorphonuclear eosinophils 2-3% Polymorphonuclear basophils 0.4% NON-GRANULOCYTES Monocytes 5.3% Lymphocytes 30% Granulocytes and monocytes are formed and stored only in bone marrow Lymphocytes and plasma cells are formed and stored mainly in various lymphoid tissue such as lymph node, spleen, thymus and tonsils as well as in bone marrow. GRANULOCYTES 4 to 8 hours in blood and 4 to 5 days in tissues MONOCYTES Monocytes also have a short transit time: 10 to 20 hours in blood and In tissue they swell to much larger size to become tissue macrophages. LYMPHOCYTES weeks to months neutrophil . 60-70% of leukocytes nucleus: 2-5 lobes Counting the number of lobes and grouping them is called Arneth count. Shift to left means (increase no of young and predominant WBCs) e.g During acute infection. Shift to right means, old cells are predominant. e.g During recovery phase NEUTROPENIA Decrease in neutrophils count Typhoid AIDS and viral hepatitis Kalazar fever Bone marrow depression by drugs and radiations NEUTROPHILIA Increase in neutrophils count Appendicitis , Tonsillitis, Pneumonia Burns, Hemorrhage, MI, Pain Hypoxia, Pregnancy BASOPHIL Their cytoplasmic granules take up basic dyes and appear deep blue MAST CELLS are derived from basophils under the influence of interleukins 3 and 4 Under many allergic conditions basophils and mast cells bursts and releases Histamine Bradykinin Serotonin Slow reacting substance of anaphylaxis Heparin Lysosomal enzymes It is the capacity of the human body to resist and destroy the invading organisms or toxins.

1. WHITE BLOOD
CELLS
Maryam Fida (o-1827)
Source:The Guyton and Hall Physiology

2. WHITE BLOOD CELLS
(Leukocytes)
•Leukocytes orWBCs are the mobile units of the
body’s immune defense system.
•Immunity is the body’s ability to resist or eliminate
potentially harmful foreign materials or abnormal
cells.
•WBC count: 5000 to 11000/ul of blood

4. TYPES OFW.B.C
• GRANULOCYTES
1. Polymorphonuclear neutrophils 60-70%
2. Polymorphonuclear eosinophils 2-3%
3. Polymorphonuclear basophils 0.4%
• NON-GRANULOCYTES
1. Monocytes 5.3%
2. Lymphocytes 30%

5. GENESIS OFW.B.C
•Granulocytes and monocytes are formed and stored
only in bone marrow
•Lymphocytes and plasma cells are formed and stored
mainly in various lymphoid tissue such as lymph node,
spleen, thymus and tonsils as well as in bone marrow.

7. LIFE SPAN OFW.B.C.
• GRANULOCYTES
4 to 8 hours in blood and 4 to 5 days in tissues
• MONOCYTES
• Monocytes also have a short transit time:
• 10 to 20 hours in blood and In tissue they swell to much larger size
to become tissue macrophages.
• LYMPHOCYTES
weeks to months

8. GRANULOCYTES
1. NEUTROPHIL
• . 60-70% of leukocytes
• nucleus: 2-5 lobes
• Counting the number of lobes and grouping them
is called Arneth count.
• Shift to left means (increase no of young and
predominantWBCs) e.g During acute infection.
• Shift to right means, old cells are predominant.
e.g During recovery phase
• NEUTROPENIA
• Decrease in neutrophils count
• Typhoid
• AIDS and viral hepatitis
• Kalazar fever
• Bone marrow depression by drugs and radiations
• NEUTROPHILIA
• Increase in neutrophils count
• Appendicitis ,Tonsillitis, Pneumonia
• Burns, Hemorrhage, MI, Pain
• Hypoxia, Pregnancy
• 3 types of granules
1. Specific
• Most abundant .
• collagenase, phospholipase and
Lysozymes
2.Azurophilic
lysosomes
3.Tertiary
• Gelatinase , collagenase help in
movement in connective tissue
• Function
a. defense against bacterial infection
b. amoeboid movement, margination,
diapedesis, chemotaxis (C5a) and
phagocytosis

10. 2. EOSINOPHIL
• Constitute about 2 -3%.
• Nucleus is bi-lobed giving appearance
of spectacle.
• Acidophilic granules are present.
• Are weak phagocytes
• FUNCTIONS
• KILLING PARASITES
• a. Releasing hydrolytic enzymes
• b. Highly reactive form of oxygen
• c. Releasing major basic protein
• Eosinophilia
• Allergic conditions
• Parasitic infections
• Collagen vascular diseases e.g. rheumatoid
arthritis
• Addison’s disease
• Drugs like aspirin, penicillin and streptomycin
• Eosinopenia
• Administration of glucocorticoids
• Over activity of adrenal cortex

11. Basophils
• Their cytoplasmic granules take up
basic dyes and appear deep blue
• MAST CELLS are derived from
basophils under the influence of
interleukins 3 and 4
• Under many allergic conditions
basophils and mast cells bursts and
releases
• Histamine
• Bradykinin
• Serotonin
• Slow reacting substance of
anaphylaxis
• Heparin
• Lysosomal enzymes
• Basophilia occurs in:
• 1) Small pox
• 2) Chicken pox

12. AGRANULOCYTES
MONOCYTES
• Agranulocytes
• Large mononuclear cell
• Kidney shaped or horse shoe shaped nucleus
• Originate in bone marrow
• Circulate in blood
• In connective tissue differentiate into
macrophages
• Monocytosis occurs in:
• 1) tuberculosis
• 2) Syphilis
• 3) malaria
• 4) kala azar
• 5) Glandular fever
LYMPHOCYTES
• Helps in immunity.

13. IMMUNITY
It is the capacity of the human body to resist and
destroy the invading organisms or toxins.

14. Development of Lymphocytes
• Lymphocytes are the vital component of immune system which includes
bone marrow, thymus, spleen, lymph nodes, tonsils, Peyer’s patches,
appendix.
• Earliest ancesters first appear in the primitive yolk sac during the first
trimester of pregnancy.
• Later during the second and third trimester these are found in the liver
and spleen.
• The PHSC give rise to CFU & LSC.
• The LSC give rise to lymphoblasts & then to lymphocytes.
• The lymphocytes designate to develop cellular immunity migrate into
thymus gland and are transformed intoT-lymphocytes.
• The lymphocytes designate to develop humoral immunity are processed
in liver during fetal life and bone marrow after birth and are transformed
into B lymphocytes.

15. T lymphocytes
Types ofT lymphocytes:
1) Cytotoxic or killer
kill bacteria or organism by CD8 By producing a
protein perforin, it produces perforation in bacterial
cells.
2) HelperT cells
Produce lymphokines or cytokines CD4, which
regulate many aspects of immune system.
1) helps macrophage in antigen processing.
2) regulate function of B-lymphocytes
3) regulate killer cells
4) regulate suppressor cells
They are damaged by AIDS virus results in AIDS.
3) Suppressor or regulatory
• Regulate the function of helper and killerT cells.
These help in immune tolerance for bodies own
cells.
4) MemoryT cells
When the body is exposed to to the same antigen
second time, the memory cells identify the organisms
and immediately activate the otherT cells. So, the
invading organism is destroyed very quickly.
B lymphocytes
• Activation of B lymphocytes, Proliferation of
plasma cells, production of more amount of
antibodies by B lymphocytes.
• Are involved in humoral immunity.
• When antigen activates the B lymphocytes,
there is formation of Plasma blast→ Plasma
cells, which have got highly developed
endoplasmic reticulum.
• Five types of Immunoglobulins:
• IgA, IgE, IgM, IgD, IgG (IgM is formed first on
the exposure of antigen and than IgG are
formed)
• 75% is IgG.
• Antibodies act on antigens directly or
indirectly

16. Types of Immunity
1. Innate immunity:
• This type involves general and not specific
processes, such as:
• i) phagocytosis of bacteria by phagocytes of
the blood and tissues
• ii) certain enzymes (e.g.lysozymes) that can
destroy bacteria non-specifically.
Acquired immunity
• Depends on the presence of specific proteins
called antibodies. It is sub-classified into two
types:
• a) Passive b) Active.
• A) Passive immunity:
• It is produced by administration of already
made antibodies, e.g., serum obtained from
actively immunized horses or human serum
rich in antibodies against invading bacteria,
viruses.
• B)Active immunity:
• This type of immunity results when the body
of a human being itself produces an immune
reaction in response to the entry of antigen
into the body.

17. Active Immunity
• It is of two types:
i) Humoral Immunity:
Plasma cells derived from B
lymphocytes (interleukins derived
fromT cells and monocytes
stimulate transformation of B
cells into antibody-forming
plasma cells)
 Plasma cells manufacture
gamma globulins which are called
as (Immunoglobulins).
They enter the plasma and
referred as humoral antibodies.
• Cell-mediated immunity:
• There is formation of activated or
sensitizedT lymphocytes that are
specially designed to destroy the
foreign agent (antigen) against
which these cells have been
activated.
• BothT and B lymphocytes affects
the activity of each other.

18. Humoral Immunity
• Is by antibodies (gamma globulins) produced by the plasma cells.
• It is the major defensive mechanism against the bacterial infection.
• When antigen presenting cells present the antigen to B lymphocytes
along with HLA, they activate the B cells and also helperT cells.
• B cells proliferate and transformed into plasma cells and memory
cells.
• The plasma cells produce the antibodies:
• Which are globulin in nature. (about 2000 mol. of antibodies per
second produced by plasma cell).
• Types: IgA, IgD, IgE, IgG, IgM.

19. Humoral Immunity
•The molecule of an immunoglobulin consists of a
portion which binds to the polymorphonuclear
leucocytes or macrophages and another portion
which binds specifically with the antigen that
produced the specific antibodies.
•If the same antigen gets into the body again, a
specific antigen-antibody reaction is produced.
•IgG is the major component in most antibody
responses.

20. •IgM is often the first antibody to appear on entry of
the bacteria or viral antigens.
•IgA is especially prominent in GIT and respiratory
tract and IgE is important in certain allergic
diseases.
•Function of IgD is unknown.
•Both IgG and IgM are opsonins.

21. Monocytes-Macrophages cell
system(Reticuloendothelial system)
1. First line of defense
With in minutes Fixed
tissue macrophages
Tissue macrophages in liver
= kupffer cells
Tissue macrophage in skin
= Histiocytes
Tissue macrophage in brain = Microglia
• . Second line of defense
• with in 1st hour or so Neutrophils
• 3.Third line of defense
• several days Invasion of monocytes and then
in tissues becoming macrophages
• 4. Fourth line of defense
• takes 3 to 4 days Increased production of
granulocytes and monocytes in bone marrow

22. • LEUKEMIAS
• Uncontrolled production ofW.B.C .
• LEUKOCYTOSIS
• Controlled production ofWBC
• LEUKOPENIA
• Bone marrow produces very few or stop
producingW.B.C
• CAUSES
• Aplasia of bone marrow caused by
• Irradiation
• Certain drugs like benzene,
chloramphenicol
•
• Direct action:
• A) Include precipitation
• B) Agglutination
• C) Neutrilization
• D) Lysis
• Indirect action:
• Is through activation of complement system
• Inactive proteins present in body fluid,
activated in a cascade manner.
• C4a, 3a, 5a activate mast cells and basophils.
• C3b causes opsonization.
• C5a is powerful chemotatic agent