Immune system and immunity

For More Medicine Free PPT - http://playnever.blogspot.com/
For Health benefits and medicine videos Subscribe youtube channel - https://www.youtube.com/playlist?list=PLKg-H-sMh9G01zEg4YpndngXODW2bq92w

1. THE IMMUNE SYSTEM and
IMMUNITY

2. Immune System
§a biochemical complex that protects the
body against pathogenic organisms and
other foreign bodies.
§The structure, cells and soluble
constituents that allow the host to
recognize and respond to foreign
stimulus.

3. Primary Role of The Immune
Syatem
§Surveillance and destruction of
substances that are foreign to the body.

- bacteria, viruses, parasites or fungi

4. Primary Function of the Immune
System
1. To protect the body against invasion by
so called non-self substance.
(any and all substances that are considered
“foreign”)
2. To differentiate between “self” and “non-
self” and to destroy that which is “non-
self”

5. Origin, Destination and Structure
of the Cells and Tissues

6. Bone Marrow
lconstitutes almost 5% of the total body
weight and is responsible for the formation
of all blood cells in adult

7. Stem Cells
lall cells originates from undifferentiated
pluripotential hemopoietic stem cells, which
can be found first in the mammalian
embryo with in the liver then the spleen.
lare pluripotential CD34+

8. §Erythropoiesis
loccurs when a CFU-S cell gives rise to
burst-forming units-erythrocytes
§granulocytopoiesis
lthe generation of three types of
granulocytes
§monocytes
lmore pathogenic than neutrophils or
eosinophils

9. Dendritic Cells
lare bone marrow derived cells specialized
for presenting antigens to either CD4+ or
CD8+ t cells in order to initiate a primary
immune response.

10. Thymus
lis a primary lymphoid organ that is
required for the generation of
immunocompetent CD3+4+ & CD3+8+
cells necessary for an adaptive immune
response.

11. Lymph Nodes
lare encapsulated structures that are
strategically placed throughout the body to
receive and filter antigens & cells from
peripheral interstitial fluid and lymph.

12. Localization of Cells
1.Superficial cortex
lcontaining primary & secondary follicles
with germinal centers containing dark and
light zone
2. Deep cortex
lcontaining high endothelial post-capillary
venules
3. Medulla
lwith medullary cortex

13. Spleen
§is an encapsulated organ
with lymphoid tissue called
white pulp(WP), which can
respond to blood-borne
antigens surrounded by the
red pulp(RP).
§Mucosal Associated
Lymphoid Tissue (MALT)

14. T Cells
§about half of the stem cells migrates to
the thymus gland where they
differentiate into T lymphocytes or T
cells
§small lymphocytes found in the blood
§about 70%-80% of the lymphocytes in
peripheral blood are T cells.

15. Two immunologic Functions of T
cells
1. Effector
lincludes the cytolysis of virally infected
cells & tumor targets & the production of
lymphokines
2. Regulator
lincludes the ability to amplify or suppress
other effector lymphocytes

16. Most of the T-cells express three
of the following CD Markers
§CD2
§CD3
§CD4
§CD8

17. Two Subpopulation of T cell in
the Circulation
1. Those with CD2, CD3, CD4 phenotype
2. Those withCD2 ,CD3, CD8 phenotype

18. includes:
1. Helper T cells (Th cells)
2. Suppressor T cells ( Ts cells)
3. Cytotoxic T cells (Tc cells )
4. Delayed hypersensitivity T cells (Td cells)

19. B cells
§Other lymphocytic stem cells
differentiate in the liver & intestinal
lymphoid areas into B lymphocytes or B
cells.
§About 10%-15% of the lymphocytes in
peripheral blood are B cells.
§Each is capable of producing hundreds
of specific antibodies per second

20. IMMUNITY
in positive sense:
lproviding natural resistance, recovery, and
acquired resistance to infectious disease.
in negative sense:
lmay result in rejection of a life-saving
transplant

21. Types of Immunity

22. Natural or Innate
lpresent at the time of birth or that
develops during maturation

23. - refers to anatomical, cellular, and humoral
defenses that function in the early stages
of host defense response to foreign
substances (antigens)
- cells that function in innate immunity does
not possess immunological memory.
- they are nonspecific because the cells do
not express receptors specific to one
particular antigen.

24. Acquired or Adaptive
lwhich is acquired as a result of prior
experience with a foreign substance

25. Further divided into:
humoral immunity (gut associated tissue GALT)
lis mediated by the antibody secreted by terminally
differentiated B cells, the plasma cells
lType I, II, III hypersensitivity reactions
Cell mediated immunity (Thymus)
linvolves T cells that recognize antigen in an MHC-
restricted fashion
(CD4 - T-helper cells, CD8 - T-suppressor cells)
ltissue graft rejection, delayed hypersensitivity
reaction, mononuclear inflammatory reaction

26. Characteristic of Natural
Immunity
1. Do not possess immunologic memory
2. Non specific
•operates as the first line of defense against
pathogens
includes the Physical barriers:
– Skin
– Mucous membrane
– Susceptibility & nonsusceptibility
– The provision of an unfavorable environment for the
infecting organism

27. Host defense in Innate Immunity
1. Cells
lantigen presenting cells
lbasophils
leosinophils mast cells natural killer cells
phagocytes
2. Humoral Factors
lcomplement proteins
llactoferrin (present in tears, sebaceous & sweat glands)
llysozymes

28. 3. Anatomical Barriers
lcilia
lmucus membrane
lskin
4. Resident Flora
lmainly nonpathogenic bacteria
lprevents colonization of new
microorganisms.
(intestine, vagina & nasopharynx)

29. Other factors that forms the
overall action of innate immunity
1. Inflammation
2. Complement
3. Phagocytosis

30. Adaptive immunity
1. Acquired adaptive immunity
lis highly specific, inducible, discriminating &
unforgetting.
- cell surface receptors are specific for a particular antigen.
- memory because lymphocytes that have been
activated in response to a particular antigen will
respond much faster in a subsequent exposure to
the same antigen.
lT lymphocyte dependent response.

31. TwoTypes of Adaptive immunity
1. Acquired active immunity
lby actual infection or inoculation that
causes the production of specific protective
antibodies
(vacines - hepatitis, tetanus)
2. Acquired passive immunity
lafford temporary protection against
invading antigen.
(RhIg given during birth, HBIg)

32. Characteristic of Adaptive
Immunity
1. With Memory
2. Specific

33. Host Defense in Adaptive
immunity
1. Cells
lB cells
lplasma cells
lT cells (cytotoxic & helper cells)
2. Humoral factors
lantibodies
lcytokines

34. Factors involved in the degree of
infection
§size of infecting dose
§route of administration
§type of infective agent

35. Nothing is predestined: The
obstacles of your past can
become the gateways that
lead to new beginnings.
Thank you and God
bless!!!