It's helpful for last time revision and it include mostly everything about WBC.

1. White blood cells (WBCs)

2. Leukocytes
• Leukos (Greek word) – white.
• Largest blood cells but account for only about 1% of the blood
volume.
• They contain nuclei and some have granules in their cytoplasm.

3. Function.
• In defence and immunity detect foreign particles and destroy it.
• Rising WBCs in the blood steam usually indicate a physiological
problem.
Eg-: Infection
• Life span – half of 15 days.

4. Types of WBCs.
• Based upon granules in their cytoplasm, they are of 2 main types:-
WBCs
1. Granulocytes
(Polymorphonuclear)
2. Agranulocytes
• Based on the dyes they take up when stained in the lab, they
are further classified as.

7. Neutrophils (polymorphs)(40-75%).
• It’s nucleus is multilobed.
• Highly moveable squeez through capillary wall in the affected area by
diapedesis towards the site of infection by chemotaxis.
• Small scavengers, protect the body against bacterial invasion such as
acute inflammation as first responders.
• Attract in large numbers to any area of infection by chemicals called
chemotoxines, released by damage cells.
• Their granules are lysosomes containing enzymes to digest engulfed
material by phagocytosis.

8. • Life spane – 6 to 9 hours.
• Pus- dead tissue cells micobes.

9. Eosinophils (1-6%)
• Less active than neutrophils, but capable of phagocytosis.
• Special role in the elimination of parasites such as worms and allergic
reaction.

10. Basophils(0-2%)
• Rise in number is seen in allergy or acute hypersensitivity reaction.
• Basophils are released by an allergen (stimulus) (an antigen that
cause allergy).
• Produces heparin (an anticoagulant), histamine (an inflammatory
agent).
• Important role in healing process.
• Mast cells – resembles basophils, found along the blood vessels do
not enter blood stream.

11. Agranulocytes
Monocytes (2-10%)
• Largest white blood cells, actively motile and phagocytic
• Some migrate into the tissue where they develop into macrophages
and clean up dead cells by phagocytosis.
• Rise in number seen in chronic infection

12. Monocyte – macrophage system
(Reticuloendothelial system)
• Consist of network of monocyte and
macrophages ( big eaters,actively
phagocytic)
• Some macrophages are mobile,whereas
others are fixed providing effective defence
at key body locations.
• Central role in non- specific and specific
body defence ( immune) and factors
important in inflammation and repair.

13. Lymphocytes (15-40%)
• Smaller than monocytes, have large nuclei.
• Some circulate in the blood but most are found in the tissues (
lymphatic tissue such as lymph nodes and spleen).
• Rise in number seen in viral infection and chronic infection.

14. Types of lymphocytes

15. T-cells
• Produce in bone marrow and some lymphatic tissues, but mature in
thymus gland.
• T- cell provide cell mediated immunity.
B- cells
• Produce and matured in bone marrow.
• Produce antibodies ( immunoglobulins) and destroy an antigen.
• Provide antibody mediated immunity.