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Visit:
Inflammation
;
Inflammatory cells in acute and chronic
inflammation
;
Acute Inflammation
;
Chemical Mediators
;Chronic Inflammation
;
Wound Healing
.
Types of acute inflammation:
1. Catarrhal type-
Mild inflammation in mucous membrane and is characterized by copious
outpouring of mucus along with desquamated epithelial cells and a few
leucocytes. Example: Common cold, catarrhal appendicitis etc.
2.
Serous type-
Mild inflammation in serous surface such as pleural
cavity joint cavity etc with accumulation of low protein containing
fluid (effusion). Example: Tuberculous pleurisy. It is also seen due to
repeated mild trauma. Example: Common blisters.
3.
Fibrinous type-
Characterized
by outpouring of exudates with high protein and less volume. Commonly
seen in serous surface such as pleura, peritoneum, pericardium. Two contiguous surfaces covered in fibrin tend to stick together and if not lysed scar tissue is formed with permanent loss of function
- Example:
Adhesive and constrictive pericarditis.
Lobar
Pneumonia
due to
Streptococcus pneumoniae is associated with massive fibrinous exudates in the lung
alveoli.
Visit:
Pericardial Disease

Lobar pneumonia
shows massive fibrinous inflammatory exudates in alveoli.
4.
Membranous type-
Fibrinous
inflammation in which network of fibrin entangling inflammatory
cells and bacteria forms pseudo-membrane. Example:
Diphtheria , Bacillary
dysentery.

Pseudomembranous
inflammation in diphtheria showing network of fibrin entangling
inflammatory cells. Bacteria forming pseudo-membrane (left).
5.
Suppurative or purulent type-
Usually caused by pyogenic bacteria and is characterized by pus
formation Example: Abscess.
Abscess:
Abscess is the localized collection of pus,
commonly seen solid block of tissue - Example: dermis, liver, kidney, brain
etc. Pus consists of partly or completely liquified dead tissue mixed
with dead or dying neutrophils and living or dead bacteria,

Pyemic
abscess in myocardium.
Abscess containing necrotic cell
debris, colonies of bacteria, and large number of neutrophils, many
of them degenerate.Myocardium is on the right.
Microscopic feature:
Central purulent zone is surrounded from inside outwards
by, pus cells, living neutrophils and granulation
tissue known as pyogenic membrane. This last layer represents the repair
process and serves as a barrier to the spread of inflammation. It also
prevents the discharge of pus from the abscess without which healing cannot occur. When pus is drained the granulation tissue proliferates to
replace the necrotic tissues and repair is done.
6. Phlegmonous type-
(Phlegmon means fire): Characterized by woody hardness of
the inflamed area due to low resistance of the body and high virulence
of the bacteria - Example: Erysipelas, pelvic cellulites etc.

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