Lectures mechanisms of disease I
Theme 1 the immune system and its opponents
Lecture 1 introduction
It is most of the time not completely clear why a disease is formed.
Lecture 2 introduction to the immune system
Parham chapter 1,2,10
There are al lot of pathogens and all are different
3 layers of defence mechanisms
1. Physical, chemical and microbial barriers
2. Innate immune system, the signal is a bit larger than the first one
3. Adaptive immune system
Respiratory tract
Tight junctions between cells, some areas with space (mucus cells)
Cilia (little hairs) to wipe out the mucus out the longs to the mouth for example, prevents
bacteria kolonization
When there is something wrong
there is an immidiate response to
get rid of those bad cells by tissue
residence cells
,Cells
o Cells between are red blood cells
Don’t have a nucleus
o Lymfocyten
Small, not much cytoplasma
o Monocytes
More cytoplasm, bit bigger
o Neutrophil
Little vesicles with lithic enzymes
o Eosinophil
Vesicles
o Basophil
For allergic responses
Innate immunity (primitive form of immune system)
Immune cells start with the hematopoetic stem cells
All kind of other types like macrophage, NK cells, dendritic cells and mast cells.
o Rapid response (hours)
o Fixed
o Limited number of specificities
o Constant during response
Adaptive immunity
Adaptive immune system
B- and T- lymfocytes
o Slow response (days to weeks)
o Variable
o Numerous highly selective specifies
o Improve during response
→ They both come together for the destruction of pathogens.
,Lack of these immunity the infection can take very long
• Innate immune system
You die because the adaptive immune system is not
working very fast.
• Adaptive immune system
Initially a little bit control but when the adaptive system
needs to take over, you will also die.
Location of the immune cells
There are a lot of immune cells in the blood.
Primary/secondary lymfoid organs contain a lot of T- and B-
cells. All those lymfe nodes are connected with each other.
Ductus thoracicus collects all the lymfe, after this it will go into the circulation.
Primary: thymus, bone marrow
Secondary: spleen, gut associated lymfathic tissue, adenoid, tonsil
B-cells are produced in the bone marrow
and they are mature.
T-cells are at first precursors in the bone
marrow and they develop in the thymus.
Mature T-cells leave the thymus and
travel to the secondary lymfoid tissues.
, Most of the secondary lymfoid tissue is localized in the gastro-intestinal tract
• GALT (gut associated lymfoid tissue)
Tonsils, adenoids, appendix, mesenteric lymfnodes. Peyer’s patches
• BALT (bronchus associated lymfoid tissue)
All lymfnodes draining respiratory epithelium
• MALT (mucosa-associated lymfoid tissue)
Remaining more diffusely organized lymfoid structures at all mucosal surfaces
Lymf node route
o Afferent vessel
o Marginal sinus
o It goes to the centre
o In the medulla the lymf is collected
o Efferent vessel
o Next lymf node or ductus thoracicus
There is also an incoming artery, outgoing vein for oxygen
T- and B-cells live in different areas
- Yellow: B-cells
- Blue: T-cells
- Red: plasma cells produce
antibodies