1. THE
PHYSIOLOGY
OF
IMMUNITY
_______________________
Delfin Arnel D. Razon, MD., DPBA
Department of Medical Physiology
Pamantasan ng Lungsod ng Maynila
College of Medicine

2. Cells Mediating the Immune
Response:
Leukocytes
granulocytes
monocytes
lymphocytes
B cells
T cells
cytotoxic T cells
helper T cells
suppressor T cells
NK cells
Plasma cells
Macrophages
Mast cells

3. IMMUNE SYSTEM
Innate immunity Acquired immunity
defences at body surfaces
phagocytosis Humoral Immunity
inflammation Cellular Immunity
complement activation

9. PHAGOCYTOSIS
• 3 Important Cells
1. Neutrophils
Circulating pool
Marginated pool
.respiratory burst
.signal transduction/stimulus response
coupling
2. Circulating monocytes
3. Fixed tissue macrophages

10. ACUIRED IMMUNITY
(ADAPTIVE IMMUNITY)
• LYMPHOCYTES
• T-cells
• B-cells
.plasma cells
IgG IgD
IgA IgE
IgM
. NK cells
• RECEPTORS
• recognition

13. HUMAN T cell

15. Human Immunoglobulins
Antibody Location Function
IgA Gut, respiratory tract and
urogenital tract mucosa
-prevents colonization of
pathogens
-localized protection in
external secretions
IgD Antigen receptor on B cells
IgE - complement fixation
majority of Ab based
immunity
-binds to allergens and
triggers histamine release
-involved in allergy
protection vs parasitic
worms
IgG - - complement fixation
- majority of Ab based
immunity
IgM Surfaces of Bcells/secreted
form
- Complement
fixation
- Pathogen
elimination in early
stages of B cells
response

21. T cell response
ANTIGEN PRESENTATION
• APCs
• MHCs
MHC class I- all nucleated cells of
the body
MHC class II- macrophages, macro-
phage-like cells, B cells
• MHC restrictions
Helper T cells = MHC class II restricted
Cytotoxic Tcells = MHC class I restricted

22. NK cells physiologic role

23. CLONAL DELETION
And
CLONAL INACTIVATION

27. END