White blood cells, or leukocytes, are nucleated blood cells that play an important role in the immune system. Compared to red blood cells, white blood cells are larger in size and fewer in number. The main types of white blood cells are neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Each type has a distinct shape and granule composition and serves different immune functions, such as phagocytosis of pathogens by neutrophils and antibody production by B lymphocytes. White blood cell counts can vary in different physiological and pathological conditions to help fight infection and disease.

1. WHITE BLOOD CELLS
White Blood Cells: Battling Blood Cells
Dr.Ashwini A. Nimbal M.D. (Ayu)
Associate Professor and HOD Kriya Shareera
BLDEA’s AVS Ayurveda Mahavidyalaya Vijayapur

2. • White Blood Cells or Leukocyte is the colorless and
nucleated formed element of blood. Leuko Means
White or colorless.
• Compared to RBC, the WBC are larger in size and
lesser in number.
• Leukocytes play very important role in defense
mechanism of the body and protect the body from
invading organisms by acting like soldiers.

3. Difference between RBC and WBC
RBC WBC
4 to 5.5million / cu mm 4,000 – 11,000/ cu mm
Smaller in size Larger in size
Biconcave or disc shape Irregular in shape
Non nucleated Nucleated
No types Many types
- Granules are present in some
types
120 days life span Shorter life span
Vital role in transport of
respiratory gases
Play important role in defense
mechanism

4. Types of WBCs
Depending upon the presence or absence of granules in the
cytoplasm, the leukocytes are classified into 2 types namely-

5. White cells, or leukocytes , exist in variable
numbers and types but make up a very small
part of blood's volume--normally only about
1% in healthy people.
Leukocytes are not limited to blood.
They occur elsewhere in the body as well,
most notably in the spleen, liver, and lymph
glands.

6. PROPERTIES OF WBC’s
1. Diapedesis: is the process by
which the leukocytes squeeze
through the narrow blood vessel.
2. Amoeboid Movement:
Neutrophils, Monocytes, Lymphocytes
show amebic movement
characterized by
protrusion of the
cytoplasm and change
in the shape

7. 3. Chemotaxis: is the attraction of WBCs towards
the injured tissues by the chemical substances
released at the site of injury.
4. Phagocytosis: Neutrophils and monocytes engulf
the foreign bodies by means of phagocytosis.

8. NEUTROPHILS / Polymorphs as it has fine granules in the
cytoplasm:
• Size : 10- 12 µm diameter
• Shape: Ameboid
• Nucleus : purple, multi lobed
• Lobes :2,3 upto 5 or more. Young cell—less lobes/
no lobes.
• Cytoplasm :blue , granular
• Granules : fine, take both acidic and basic stains and
appears violet in color.
• Life span :2-5 days

9. Functions of Neutrophils : Phagocytosis – 1st line of defense
• The neutrophils are the free cells in the body and wander freely
through the tissue and practically no part of the body is spared by
these leukocytes.
 Substance present in granules and cytoplasm:
• Enzymes like proteases, myeloperoxidases, elastases and
metalloproteinases – destroys the microorganisms.
• Antobody like substances calledd defensins ( antimicrobial peptides) –
which are active against bacteria and fungi.
 The membrane of neutrophils contain an enzyme – NADPH oxidase
(dihydronicotinamide adenine dinucleotide phosphate oxidase) – it is
activated by the toxic metabolites released from infected tissues and
then act as a bactericidal.
 Neutrophil also secrete paltelet activating factor (PAF) which is a
cytokine – it accelerates the aggregation of platelets during injury to
the blood vessel resulting in the prevention of excess loss of blood.

10. • Mechanism of action of Neutrophils:
 At the time of infection by the microorganisms, the large
number of neutrophils are released from the blood and
also increases the production of neutrophils from
progenitor cells.
 first All the neutrophils move from blood vessels by
diapedesis and are attracted towards the site of infection
by means of Chemotaxis.

11.  Chemotaxis occurs due to the attraction by some
chemical substances called Chemoattactants, which
are released from the infected area.
After reaching the area the neutrophils surround
the area and get adhered (stick) to the infected
tissues. The chemoattractants increase the adhesive
nature of neutrophils so that the neutrophils
become sticky and attach firmly to the infected
area.
Each neutrophil can hold about 15 to 20
microorganisms at a time.
Then neutrophils start destroying the invaders or
bacteria by engulfing them by means of
phagocytosis.

12. • Respiratory burst:
Is a rapid increase in oxygen consumption during
the process of phagocytosis by neutrophils and
other phagocytic cells. NADPH oxidase is
responsible for this process. During respiratory
burst the free redical O2 –ve is formed and this
combine with 2 H+ ions and form H2O2
(Hydrogen Peroxide). Both O2-ve and H2O2 are
the oxidants having potent bactericidal action.

13. • Pus and Pus cells:
pus is the whitish yellow fluid formed in the
infected tissue by the dead WBCs, bacteria or
foreign bodies and cellular debris.
The dead WBCs are called the pus cells.
During the battle against the bacteria, many
WBCs are killed by the toxins released from the
bacteria. The dead cells are collected in the
center of infected area. The dead cells together
with plasma leaked from the blood vessel,
liquefied tissue cells and RBCs escaped from
damaged blood vessels constitutes the pus.

14. EOSINOPHILS:
• Size : 10- 14 µm diameter
• Nucleus : purple, bilobed and spectacle shaped
• Cytoplasm : which stains pink or red with eosin i.e. acidophilic
• Granules : coarse, bright red, have lysozymes
– Major basic proteins (MBP) - histaminase
– Eosinophil peroxidase (EPO)– histamine secretion
• Life span : 7-12 days

15. Functions of Eosinophils:
• Play an important role in the body against the parasites.
• During parasitic infection and also during allergic diseases
like asthma, there is production of large number of
eosinophils which move towards the tissues affected by
parasites.
• Eosinophils are responsible for detoxification, disintegration
(process of losing strength) and removal of foreign proteins.
• Eosinophils attack foreign bodies by some special type of
cytotoxic substances present in their granules.

16. BASOPHILS:
• Size : 8- 10 µm diameter
• Nucleus : bi lobed, S shaped
• Cytoplasm : basophilic, granular
• Granules : coarse, purple/ methylene blue contain
– Heparin
– Histamine
– Proteases & myeloperoxidases
• Life span : 12-15 days

17. Functions of Basophils:
• Play an important role in the healing processes.
• Also play an important role in allergy or acute
hypersensitivity reactions (allergy) because of
presence of receptors for IgE basophil
membrane.
• The functions of basophils are executed by the
release of some important substances from their
granules such as,
Heparin – prevent the intra vascular clotting
Histamine- produce the acute hypersensitivity reactions by
causing vascular and tissue responses.
Cytokine: accelerates inflammatory responses and kill the
invading organisms.

18. Mast cell: is a large tissue cell resembling the basophil.
Mast cells are developed in the bone marrow, but their
precursor cells are different. After differentiation the
immature mast cells enter the tissues. Maturation of
mast cells takes place only after entering the tissue. Mast
cells are found along with the blood vessels and are
prominently seen in the areas such as skin, mucosa of the
lungs and digestive tract, mouth, conjunctiva and nose.
These cells usually do not enter the blood stream.
Functions: The mast cell plays an important role in
producing the hypersensitivity reactions like allergy and
anaphylaxis (a severe, potentially life threatening allergic
reactions can occur within seconds or minutes of
exposure to allergen).

19. LYMPHOCYTES: Not having granulees
• Nucleus: oval shape, bean shaped or
kidney shaped. Nucleus occupies the whole
of the cytoplasm.. A rim of cytoplasm may
or may not be seen
• Can be classified in two ways
– Based on structure :
a) large : 10-12µm
b) small : 7-10 µm
– Based on maturation :
a) T Lymphocytes –80%
b) B Lymphocytes -15%
c) NK Cells-5%
• T cells – CD4 & CD8
• Life span : ½-1 day

20.  Functions of Lymphocytes: play an important role in immunity.
• Functionally are classified into 2 types,
• T Lymphocytes: Cellular immunity
– secrete lymhokines
– induction of apoptosis ( the death of cells) in target cells
• B Lymphocytes: development of Humoral immunity
– produce plasma cells- immmunoglobins
• Nk (natural Killer) cells/ large granular lymphocytes
– attack cancer cells and viruses
In detail will study this in the chapter
physiology of immunity

21. MONOCYTES: Is the largest leukocyte
• Size : 14- 18 µm diameter (largest)
• Nucleus : Pale , round, oval, horse shoe shaped,
kidney shaped or bean shaped. The nucleus is placed
either in the center of the cell or pushed to one side and large
amountof cytoplasm is seen.
• Cytoplasm : clear , pale blue , without granules.
• Life span : 48-72 hrs in blood & 3 months in tissues.
• Reticuloendothelial system :
blood monocytes + tissue macrophages

22. • Functions of Monocytes:
– like neutrophils, monocytes also are motile and
phagocytic in nature. These cells wander freely through
all tissues of the body.
– It acts as a 2nd line of defense.
By the secretions of chemical activators of inflammation
• Interleukin-1, binding proteins like transferrin,
lysozyme, proteases, Platelet Activating factor (PAF)
– hence plays an impportant role in tissue repair

23. Monocytes are the precursors of the tissue macrophages.
The matured monocytes stay in the blood only for few
hours. Afterwards these cells enter the tissues from the
blood and become tissue macrophages. Examples of tissue
macrophages are Kupffer cells in liver, alveolar
macrophages in lungs and macrophages in Spleen.

24. VARIATIONS IN WBCs
Normal Count – 4000-11000/cmm of blood
Leucocytosis – in WBC count above 11000/cmm of blood
Leucopenia –  in WBC count below 4000/cmm of blood
PHYSIOLOGICAL VARIATIONS :-
1)Diurnal :- WBC count minimum in the evening than in
the morning
2)Meals , Pregnancy, Fear, pain, anxiety & Exercise  the
count
3)Age :- Newborn :-20000/ cu mm of blood

25. PATHOLOGICAL VARIATIONS :-
Leucocytosis:
1) in Neutrophils – Acute infection , haemorrhage , operations ,
tissue damage
2)  in Eosinophils – Allergy, Parasitic infections
3)  in Monocytes – Chronic infections
) in lymphocyte – Whooping cough , Tuberculosis , leprosy
5)  in Basophils – Lead poisoning
Leukopenia:
1)  in Neutrophils – Viral infections
2)  in Eosinophils – Cortisol therapy
3) Bone marrow deseases causes in  neutrophil , eosinophil ,
basophil , monocyte

26. Leukemia:
Is the condition, which is characterized by abnormal and
uncontrolled increase in leukocyte count . More than
1,000,000/ cu mm. it is called blood cancer.
• Proliferation of leukaemic cells –Primarily in the bone
marrow
• Classification –
1)On the basis of cell types,
predominantly involved :-
a) Myeloid
b) Lymphoid
2) On the basis of natural history of disease :-
a)Acute
b)Chronic

27. Thank
You