4. Causes of inflammation
Bacterial
Viral
Protozoal
Metazoal*
Fungal
Immunological
Tumours
Chemicals, toxins etc
Radiation
*A subdivision of the animal kingdom that includes all
multicellular animal organisms having cells that are
differentiated and form tissues and organs.
5. Acute inflammation
the initial response of the body to harmful stimuli,
achieved by the increased movement of plasma and
leukocytes (especially granulocytes) from the blood into
the injured tissues.
Inflammation is not a synonym for infection.
14. Inflammation
The basis of the five cardinal signs
Increased blood flow due to vascular dilatation gives
redness and heat.
Increased vascular permeability gives oedema causing
tissue swelling.
Certain chemical mediators stimulate sensory nerve
endings giving pain. Nerves are also stimulated by
stretching due to oedema.
Pain and swelling result in loss of function.
19. The phases of inflammation
FIRST THERE IS VASCULAR DILATATION
followed by exudation of protein-rich oedema
fluid which floods the area, dilutes toxins, allows
immunoglobulins to opsonise bacteria and
provides substrate (fibrinogen) for fibrin
scaffold*.
SECOND THERE IS ACTIVE EMIGRATION OF
POLYMORPHS through vessel wall and along the
chemotactic gradient to the site of injury
make (a foreign cell) more susceptible to phagocytosis
*a temporary or movable platform
the movement of a microorganism or cell in response to a chemical
stimulus.
20. THE VASCULAR PHASE OF INFLAMMATION
Fluid escapes from vessels because of endothelial cell (EC)
retraction, opening up gap-junctions.
The vessels which are normally involved are the post-capillary
venules where the EC have high affinity receptors for histamine.
Severe EC injury leads to leakiness of all vessels capillaries,
venules and arterioles - giving acute local oedema,
e.g. blister formation after a burn.
The phases of inflammation
22. Leukocyte migration in inflammation
V: a very small vein, especially one collecting blood from the capillaries
S: Cell adhesion molecules: selectins and integrins. ... Selectins comprise a family of
three members (E-, P-, and L-selectin) that are differentially expressed by leukocytes
and endothelial cells, and are involved in the early steps of leukocyte extravasation.
Integrins are the
principal receptors
used by animal cells to
bind to extracellular
matrix. They are
heterodimers
& function as
transmembrane linkers
b/w the extracellular
matrix and the actin
cytoskeleton.
24. Acute inflammation: tissue effects
Pavementation and diapedesis
Leukocyte extravasation, less commonly called diapedesis, is the movement of
leukocytes out of the circulatory system and towards the site of tissue damage or
infection. This process forms part of the innate immune response, involving the
recruitment of non-specific leukocytes
30. Vasoactive amines
Histamine
Serotonin (5-HT)
Neuropeptides
Substance P
Plasma proteases and the complement system
Action of Hageman factor
Arachidonic acid metabolites
Prostaglandins
Leukotrienes
Lipoxins
Cytokines
IL-1, TNF etc.
Chemokines (CXC and CC)
Nitric oxide and oxygen-derived free radicals
Chemical mediators of inflammation
31. Chemical mediators of inflammation
PREFORMED
Histamine, Serotonin
NEWLY SYNTHESISED
Prostaglandins
Leucotrienes
Platelet activating factor
Cytokines
Nitric oxide
LOCAL AND SYSTEMIC*
*mechanisms by which local immune stimulation is transmitted to
the periphery, leading to systemic inflammation. We concentrate
on the role of three signalling molecules: interleukin-1,
interleukin-6, and tumour necrosis factor alpha. These cytokines
provide a direct link between local and systemic inflammation
33. Plasma proteases
Kinins are polypeptides and cause vasodilation and smooth muscle contraction. These
structurally related polypeptides, such as bradykinin and kallidin are members of the
autacoid family. They act locally to induce vasodilation and contraction of smooth
Kinins: any of a
group of
substances
formed in body
tissue in
response to
injury.
36. Arachidonic acid
Arachidonic acid; 506-32-1; Arachidonate; Immunocytophyte;
(5Z,8Z,11Z,14Z)-icosa-5,8,11,14-tetraenoic acid; (all-Z)-
5,8,11,14-Eicosatetraenoic acid
Molecular Formula: C20H32O2
Molecular Weight: 304.474 g/mol
Arachidonic Acid is an unsaturated, essential fatty acid. It is found in animal and human
fat as well as in the liver, brain, and glandular organs, and is a constituent of animal
phosphatides. It is formed by the synthesis from dietary linoleic acid and is a precursor
in the biosynthesis of prostaglandins, thromboxanes, and leukotrienes.(ChemID Plus)
The beneficial effects of Omega-3 fatty acids are believed to be due in part to selective alteration
of arachidonate metabolism that involves cyclooxygenase (COX) enzymes. (PMID: 23371504)
Here, 9-oxononanoic acid (9-ONA), one of the major products of peroxidized fatty acids, was
found to stimulate the activity of phospholipase A2 (PLA2), the key enzyme to
initiate arachidonate cascade and eicosanoid production.
(PMID: 23704812) Arachidonate lipoxygenase (ALOX) enzymes metabolize arachidonic acid to
generate potent inflammatory mediators and play an important role in inflammation-associated
diseases. (PMID: 23404351)
37. Cytokines (IL-1 and TNF)
Cytokines : any of a number of substances, such as interferon,
interleukin, and growth factors, which are secreted by certain cells
of the immune system and have an effect on other cells. They are
small secreted proteins released by cells have a specific effect on
the interactions and communications between cells.
41. PHAGOCYTOSIS
Recognition and attachment
Foreign objects coated with opsonins IgG and C3b which attach to
receptors on polymorph surface.
Engulfment
Cell membrane fuses around an object: at the some time
lysosomes
empty into the vacuole, often before vacuole has time to seal - this
gives
rise to 'regurgitation during feeding' and enzymatic damage to
surrounding
tissue.
Killing or degradation
H2O2, hypohalous acid (HOC1) produced by myeloperoxidase and
superoxides kill bacteria. Lysozyme digests them.
52. Granuloma
Definition
A collection of macrophages, lymphocytes,
mononuclear cells and fibroblasts with or
without giant cell formation and constitutes
a special form of chronic inflammation