2. INFLAMMATION
Literally: inflammation means "burnout".
Scientifically: it is a physiological response to cell injury, associated with cellular,
vascular humoral events
Cardinal Signs of inflammation
Rubor (redness), Color (heat), Dolar (pain), Tumor (swelling), Functio laesa (loss
of function).
1- Redness (Rubor): due to dilatation of small blood vessels and increased blood
supply (hyperemia).
2- Swelling (Tumor): due to accumulation of inflammatory fluid in the
extravascular space + the inflammatory cells accumulated in the area. (Exudate)
3- Heat (Color): due to increased blood flow (hyperemia), from vascular dilation
and delivery of warm blood to the area.
3. 4- Pain (Dolor): due to the stretching of tissues due to inflammatory
edema and the chemical mediators of acute inflammation, especially
bradykinin and prostaglandins.
5- Loss of Function (Functio laesa): due to restricted movement of an
inflamed organ by pain reflexes, and swelling may physically
immobilize the affected area.
What are the Purposes of the Inflammatory Process:
-To localize the injury in a specific area,
-To get rid of the cause of the injury
-To repair the damaged area.
4. General Features of Inflammation:
- Inflammation is a complicated process in which you will
see one mediator with different functions on different
tissues, also you can see different mediators that have the same
function.
- Duration of inflammation can be long or short, hence there
is acute, chronic, or sub-chronic (different stages),
- If acute inflammation does not heal it becomes chronic.
5. Effects of Inflammation: local or systemic, also can be useful,
or harmful
• local effects: for example, the killing of invading
microorganisms, swelling, and loss of function
• Systemic effects: like fever, malaise, and leukocytosis
Systemic Effect of Inflammation:
a. Leukocytosis: ( high white blood cells), increased neutrophils
indicate acute inflammation special bacterial infection, whereas
increased lymphocytes occur in viral infections or chronic
inflammation.
b.Fever: (elevation of body temperature) is the commonest systemic
effect of inflammation. associated with an infectious inflammation,
produced by cytokines and interleukins.
6. What is the function of fever? It improves the efficiency
of leukocyte killing and impairs the replication of the invading
organisms.
c. Increased Acute Phase Reactant & ESR:
Both are due to an increased level of IL1, IL6, TNF…etc. and
other proteins produced from the liver in association with
inflammation
7. Beneficial Effect of Inflammation:
a. Dilution effect: results in removal and washout of the bacterial toxins
through the lymphatic system away from the inflammatory areas.
b. promoting the immunity: by enhancing immune response after bringing
microorganism to the adjacent lymph node,
c. Provides WBCs. Antibodies. and proteins provide cells and different
proteins like fibrinogen, complement system, and nutrition to the sick cells to
the site of inflammation.
Harmful Effects of Inflammation:
a. Swelling: resulting in obstruction of organs with lumen as in acute, like
laryngitis, or increased intracranial pressure in encephalitis, and ischemic
injury if obstruction of blood supply takes place.
b. Loss of Organ Function: inflamed organs lose their function, for example,
hepatitis (inflammation of the liver ) is associated with impaired liver function
tests.
8. Nomenclature of the Inflamed Tissue:
The rule of nomenclature is to add the suffix (itis) at the end of the name
of the organ or tissue, for example:
Appendix: Appendicitis
Gastric tissue: Gastritis
Colon: Colitis
Ovary: Ovaritis
Mammary tissue: Mastitis
Exceptional Rule:
Pulmonary: pneumonia,
pleural: Pleurisy
Veins: Phlebitis
Testis: Orchitis
Fallopian tube: Salpingitis
9. Classification of Inflammation:
Inflammation can be classified as acute inflammation,
inflammation & chronic inflammation sub-chronic inflammation
Comparison: Acute and Chronic Inflammation:
Acute inflammation occurs during a short period of time, days or
weeks, in the presence of all cardinal signs of inflammation and
infiltration of neutrophils. While, chronic inflammation occurs over
a long period of time, months or years, and is infiltrated with
lymphocytes, plasma cells, and macrophages and forming of
fibrous tissue in the periphery of the inflamed tissue.
10. Features Acute inflammation Chronic inflammation
Duration Days or weeks Months or years
Types of
cells
Mainly neutrophils Mainly lymphocytes, and
plasma cells, macrophages
and monocyte.
Cardinal
signs
All are present Some of them
Healing
process
Complete resolution By fibrosis
