C H A P T E R 1 5
Introduction to the immune response and inflammation
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The response to the inflammatory stimuli involves
local vasodilation, increased capillary permeability
and the stimulation of pain fibres. These reactions
alert the person to the injury and bring an increased
blood flow to the area.
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The immune response provides a specific reaction to
foreign cells or proteins.
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T cells can be cytotoxic, destroying non–self-
cells; helper, augmenting an immune reaction; or
suppressor, dampening the immune response to save
energy and prevent cell damage.
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B cells produce antibodies in response to exposure
to specific antigens or proteins. Antibodies react
with this antigen to produce an antigen–antibody
complex that activates complement and will result in
destruction of the antigen.
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Other mediators that affect the immune and
inflammatory responses include interferons, tissue
necrosis factor and interleukins.
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The immune and inflammatory responses work
together to protect the body from injury or foreign
pathogens.
KEY POINTS
PATHOPHYSIOLOGY INVOLVING THE
IMMUNE SYSTEM
Several conditions can arise that cause problems involv
ing the immune system. These conditions, many of
which are treated by drugs that stimulate or suppress the
immune system, include neoplasm, viral invasion, auto
immune disease and transplant rejection.
Neoplasms
Neoplasms occur when mutant cells escape the normal
surveillance of the immune system and begin to grow
and multiply. This can happen in many ways. For
example, ageing causes a decreased efficiency of the
immune system, allowing some cells to escape detec
tion. Location of the mutant cells can make it difficult
for lymphocytes to get to an area to respond. Mutant
cells in breast tissue, for example, are not well perfused
with blood and may escape detection until they are quite
abundant. Sometimes cells are able to avoid detection
by the T cells until the growing mass of cells is so large
that the immune system cannot deal with it. Tumours
can also produce blocking antibodies that cover the
antigen-receptor sites on the tumour and prevent rec
ognition by cytotoxic T cells. In addition, a weakly
antigenic tumour may develop; such a tumour elicits a
Protein release
B cell
Plasma cells
Antibody formation
Antigen–antibody complex
Complement activation
Inflammatory reaction
Cell invasion
Helper T cells
Suppressor T cells
Interleukins
Immune reaction
Inflammatory reaction
Cell
Interferon release
Virus
Cell injury
Hageman factor
Kinin activation
Leucocyte activation
Pyretic effect
Effector
T cells
Cell death
Inflammatory response
Histamine release
Rubor
Calour
Tumour
Dolour
Memory cells
FIGURE 15.6
Interrelationship of immune and inflammatory reactions.
