1. Dr. Walid Daoud, A. Professor
Blood Week 9
Dr. Walid Daoud,
A. Professor

2. White Blood Cells (Leukocytes) ____________________________
Total leukocytic count = 4,000-11,000/mm3
Classification:
1. Granular leukocytes:
- Neutrophils.
- Eosinophils.
- Basophils.
2. Agranular leukocytes:
- Monocytes.
- Lymphocytes.

3. White Blood Cells (Leukocytes) ____________________________
Formation of Leukocytes (Leukopoiesis):
All in bone marrow except lymphocytes in lymphoid tissues (LN, thymus & spleen).
Pluripotent stem cells ↓
Colony forming unit-granulocyte-monocyte
↓ GM-CSF ↓
Myeloid line Lymphoid line
- Granulocytes Lymphocytes
- Monocytes

4. White Blood Cells (Leukocytes) ____________________________
Functions of Granular Leukocytes:
1-Neutrophils (60-70%):
The 1st line of defense against organisms.
a- Margination.
b- Diapedesis.
c- Amoeboid movement.
d- Chemotaxis.
e- Phagocytosis.

5. White Blood Cells (Leukocytes) ____________________________
2- Eosinophils (2-6%):
a- They kill parasites.
b- They increase in allergic conditions.
c- Weak phagocytosis and show chemotaxis
3- Basophils (0-1%):
a- Contain histamine and heparin.
b- Possess IgE receptors on their membranes

6. White Blood Cells (Leukocytes) ____________________________
Functions of Agranular Leukocytes:
1-Monocytes (2-8%):
a- Become tissue macrophage (RES).
b- Migration.
c- Phagocytosis.
2-Lymphocytes (20-30%):
Immune function.

7. Pathological Variation in Leukocytic Count ______________________________________
Leukopenia: Leukocytosis:
-Chronic infection After meal, during
-Drugs Exercise and stress. -Starvation Inflam., M. infarction
Agranulocytosis:
-Exposure to gamma rays.
-Drugs.

8. Immunity ____________________________
It is the ability of the body to resist almost all types of organisms and toxins.
1-Innate (non-specific) immunity:
. Resistance of skin to invasion by organism.
. Destruction of organism by gastric HCl.
. Phagocytosis.
2-Acquired (specific) immunity:
. Humoral immunity: B-lymphocytes.
. Cellular immunity: T-lymphocytes.

9. Antigens ____________________________
They are substances that are able to induce an immune response & to react specifically with its products.
They possess certain chemical structures specific to them known as antigenic determinants, molecular weight > 10,000.
Antigenic determinants are present on cell membranes or free e.g., bacterial toxins.

10. Development of Immune System ____________________________
I-Origin of lymphocytes:
In fetus, lymphocytic stem cells formed in
bone marrow migrate either:
. To thymus gland to give T-lymphocytes or
. To bursa-equivalent tissues (liver & spleen) to give B-lymphocytes.
II-Processing of lymphocytes:
1- Recognition.
2- Specification.

11. Development of Immune System ____________________________
III-Lymphocyte migration:
They migrate to live in lymphoid tissues as lymph nodes, spleen, liver & bone marrow.
Types of lymphocytes:
1- B-lymphocytes.
2- T-lymphocytes.
3- Non B non T-lymphocytes (NK cells)

12. Development of Immune System ____________________________
Varieties of B-lymphocytes:
- Plasma cells.
- Memory cells.
Varieties of T-lymphocytes:
- Cytotoxic (Killer) T-cells.
- Helper T-cells.
- Suppressor T-cells.
- Memory T-cells.

13. Major Histocompatibility Complex (MHC) ___________________________________
It is a protein on cell membrane genetically encoded by chromosome 6. Two classes:
. MHC class I protein: on all nucleated cells.
. MHC class II protein: on antigen presenting cells, mostly macrophages.
MHC proteins are specific for individual and distinguish self from non-self.
Cellular immune response occurs when foreign antigen and MHC protein are coupled and presented together to the immune system.

14. Cellular Immunity ____________________________
-Done by activated cytotoxic T-lymphocytes.
-It occurs on exposure to:
.Viruses, fungi, few bacteria e.g. TB.
.Cells from other individuals (tissue transplant)
.Tumor cells.
When cytotoxic T-cells are activated they proliferate and differentiate into clones of:
1-Activated cytotoxic T-cells.
2-Memory T-cells.

15. Humoral Immunity ____________________________
Produced by B-lymphocytes.
Mainly acts against bacterial infections.
Activated B-lymphocytes specific to antigen differentiate into:
1-Plasma cells.
2-Memory B-cells.

16. Mechanism of Action of Antibodies _______________________________
A. Direct attack of antigen:
1- Agglutination of bacteria.
2- Precipitation of antigen.
3- Lysis.
4- Opsonization.
B. Activation of the complement system.

17. Nature and Structure of Antibodies _____________________________
Antibodies are γ globulins (immunoglobulins):
IgG, IgM, IgA, IgE and IgD
Antibody is formed of light and heavy polypeptide chains bound together by disulphide (S-S) bonds known as heavy-light chain pairs. Each pair is bound to another by interchain disulphide bridges.

18. Classes of Antibodies ____________________________
-Immunoglobulin G (IgG).
-Immunoglobulin M (IgM).
-Immunoglobulin A (IgA).
-Immunoglobulin E (IgE).

19. Undesirable Consequences of Immune Response ____________________________
1-Graft rejection.
2-Auto-immune diseases.
3-Acquired immune deficiency syndrome
(AIDS)

20. Blood Groups ____________________________________________________________________________________________________________________________________________
ABO System:
A and B antigens on red cell membrane
(agglutinogen). Antibodies in plasma (agglutinins). According to presence or absence of A and B antigens, humans are divided into 4 blood groups: %
Agglutinin
Agglutinogen
B. group
40%
10% 5%
45%
anti B
anti A -
Anti A and anti B A B
A and B AB O

21. Importance of Blood Groups ____________________________________________________________________________________________________________________________________________
1-Medicolegal importance:
Determination of blood group can confirm that a certain man is not the father of a specific child, but not that he is. That is a good negative.
2-Incompatible blood transfusion:
Donor RBCs are agglutinated by recipient plasma but donor serum rarely agglutinate recipient RBCs. Therefore:
Group O is a universal donor.
Group AB is a universal recipient.

22. Blood Groups ______________________________________________________________________________________________________________________________
Rh System:
Rh factor is agglutinogen on RBCs (D antigen) in 85% of white population (Rh-positive) while who do not have (Rh-negative).
Antibody against Rh agglutinogen (anti D) normally not present in plasma and formed only when Rh-ve individual receives Rh+ve blood.

23. Importance of Rh Factor ______________________________________________________________________________________________________________________________
1-Blood transfusion:
If Rh-ve individual receives Rh+ve blood.
2-Erythroblastosis fetalis:
When Rh-ve female marries Rh+ve male leading to kernicterus of fetus.
Prevention:
-Anti D antibodies given to mother after delivery to neutralize Rh antigen.
-Rh-ve person should never receive Rh+ve bl.

24. Blood Transfusion ____________________________________________________________________________________________________________________________________________
Indications:
1-To restore blood volume as in hemorrhage
2-To restore certain blood elements:
RBCs in anemia, WBCs in leukopenia, platelets in purpura, clotting factors in hemophilia, antibodies in infection, plasma proteins in hypoproteinemia.
3-In erythroblastosis fetalis.
Dangers of incompatible blood transfusion.