#5: INFLAMMATION

u READING
What is inflammation? Inflammation has long been considered simply as the reaction
of tissues to injury, infection, or irritation. More properly, it is the reaction of
vascularized living tissues to local injury, which comprises a series of changes in the
terminal vascular bed, in the blood, in the connective tissues, which are designed to
eliminate the offending irritant and to repair the damaged tissues.
Inflammation can be mild, as in the reaction to a wood splinter in one's finger, or it
can be severe and life threatening, as in a severe bronchopneumonia. In between lies
a gray zone in which moderate inflammation occurs. All inflammatory reactions have
a beginning, and most have an end. Peracute inflammation is manifest very soon
after its initiation, perhaps only a few hours. Acute inflammation usually begins
within 4-6 hours and can remain for several days. Chronic inflammation often follows
an acute inflammatory phase or it may develop as an insidious, low-grade, subclinical
process. Acute inflammation may produce clinical signs localized to the site of injury
characterized as heat, redness, swelling and pain. In some cases they may be
accompanied by profound systemic changes such as leukocytosis and fever.
In inflammatory process, fluid and leukocytes often escape from the blood to the
perivascular tissues to form transudate or exudate.
There are four stages of inflammation
(1) Damaged tissue release histamines, increasing blood flow to the area
(2) Histamine cause capillaries to leak, releasing phagocytes and clotting factors
into the wound
(3) Phagocytes engulf bacteria, dead cells, cellular debris (phagocytosis)
(4) Platelets move out of the capillaries to seal the wounded area
Fever
Fever (also known as pyrexia, or a febrile response) is a medical symptom that
describes an increase in internal body temperature to levels that are above normal. A
fever is most accurately characterized as a temporary elevation in the body’s
thermoregulatory set-point, which is usually by about 1-2°C. This elevation in
thermoregulatory set-point means that the previous "normal body temperature"
would be considered hypothermic. Effective mechanisms, such as increased blood
pressure, increased heart rate, activation of brown adipose tissue, and muscular

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shivering attempt to counteract the perceived hypothermia, thereby reaching the
new thermoregulatory set-point. It is the most common symptom of many diseases.
Fever occurs when either endogenous or exogenous pyrogens cause an elevation in
the body's thermoregulatory set-point. Most fevers are caused by infections, and
almost all infectious diseases can cause fever. When a patient has or is suspected of
having a fever, that person's body temperature is measured using a thermometer. If
successful in ridding the body of an invasive pathogen, fever is an important
protective immune mechanism and should generally not be suppressed. However,
there are instances when fever escalates to temperatures where the body is at risk of
destroying its own cells and must be brought under control with suppressive
medication.
Fever should not be confused with hyperthermia. In hyperthermia, the set-point is
unaltered, and the body temperature becomes elevated in an uncontrolled fashion
due to exogenous heat exposure (i.e. weather condition) or endogenous heat
production (i.e. excessive exercise). Fever can be classed as low-grade (38 to 39°C),
moderate (39 to 40°C), or high-grade (more than 40°C) depending on how much the
body temperature has deviated from normal. Fever may be of benefit and is part of
the body's response to a disease; however, if the fever goes above 42°C, then it may
cause significant tissue damage. This is termed hyperpyrexia.

(a) Mast cells detect injury to nearby cells and release histamine, initiating an
inflammatory response. (b) Histamine increases blood flow to the wound site,
and increased vascular permeability allows fluid, proteins, phagocytes, and other
immune cells to enter infected tissue. These events result in the swelling and
reddening of the injured site, and the increased blood flow to the injured site
causes it to feel warm. Inflammation is also associated with pain due to these
events stimulating nerve pain receptors in the tissue.

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 u EXTENSIONS
Nomenclature of common types of inflammation
Inflammatory lesions can be classified according to different factors as follows:
Extent Duration Distribution
Minimal Peracute Focal
Mild Acute Multifocal
Moderate Subacute Diffuse
Severe Chronic Locally extensive
Body part inflammation (-'itis')
Arteries arteritis
Bile duct cholangitis
Blood vessels or lymph vessels vasculitis
Bone osteitis
Bone marrow osteomyelitis
Brain encephalitis
Bronchi bronchitis
Cecum typhlitis
Cervix cervicitis
Colon colitis
Conjunctiva conjunctivitis
Connective tissue cellulitis
Cornea keratitis
Ear otitis
Endocardium endocarditis
Endometrium endometritis
Epididymis epididymitis
Eyelids blepharitis
Eyes ophthalmitis
Fascia fasciitis
Fibrous connective tissue fibrositis
Gall bladder cholecystitis
Gingiva gingivitis
Glans penis balanitis
Heart carditis
Ileum ileitis
Intestine enteritis
Joint arthritis
Kidney nephritis
Larynx laryngitis
Liver hepatitis
Lungs pneumonitis (also pneumonia)
Lymph node lymphadenitis
Mammary gland mastitis
Meninges meningitis
Mouth stomatitis

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Muscle myositis
Myocardium myocarditis
Nasal lining rhinitis
Nerve neuritis
Ovaries oophoritis
Oviduct (fallopian tubes) salpingitis
Pancreas pancreatitis
Parotid gland parotitis
Pericardium pericarditis
Peritoneum peritonitis
Pharynx pharyngitis
Pleura pleuritis
Prostate prostatitis
Rectum proctitis
Renal pelvis pyelitis
Sinus of the skull sinusitis
Skin dermatitis
Skin and muscles dermatomyositis
Small intestine enteritis
Small intestine and large intestine enterocolitis
Spinal cord myelitis
Spleen splenitis
Stomach gastritis
Stomach and small intestine gastroenteritis
Tendon tendonitis
Testicle orchitis
Tongue glossitis
Tonsils tonsillitis
Trachea tracheitis
Umbilical cord omphalitis
Urinary bladder cystitis
Uterus metritis
Uvea uveitis
Vaginal mucosa vaginitis
Veins phlebitis
Vulva vulvitis

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 u CROSSWORD
Answer these questions and fill into the corresponding cells and then find out the
word in the shadowed column
A: the portion of the body between the thorax and the pelvis to form a cavity
containing viscera
B: an exocrine gland in the male’s genital organ secreting substances, enzymes
which account for the liquefaction of coagulant semen
C: a situation of animal to get disease easily when having no immunity and tolerance
D: the term used to describe a disease happening and disappearing suddenly in a
population
E: the ability of an animal which is developed to resist a disease by which pathogens
are inactivated in the body
F: a kind of biologicals which contain antigen used to prevent disease
G: a substance produced by, or a semisynthetic substance derived from a
microorganism and able in dilute solution to inhibit or kill another microorganism
H: a science that deals with the immune system and the cell-mediated and humoral
aspects of immunity and immune responses
I: the fourth compartment of the ruminant stomach that follows the omasum and
has a true digestive function.

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