Transcript Thymus gland Bone marrow Secondary organs of immune system

When Our Immune System
Breaks Down
Immunopathology
Our bodies are constantly at
war, under assault 24-hours a
day from infection and toxins.
That we survive
at all, is due to
our immune
system,
-a network of
chemicals & cells
that protect the
body.
Primary organs of
immune system:
•Thymus gland
•Bone marrow
Secondary organs of
immune system:
•Lymph nodes
•Spleen
•Tonsils & Adenoids
Main Job of the Immune System
• Protects body from invasion of
organisms
• Protects body from own cells
which may develop incorrectly
and cause harm to the fine
balance of the body's systems
Major cells of immune system:
Leukocytes:
1. Polymorphonuclear leukocytes
(granulocytes) - active in inflammatory
process
2. Monocytes & Macrophages - engulf and
eat pathogens 7 foreign substances
3. Lymphocytes - B & T lymphocytes
Crossing the barriers
•skin
•mucosal membranes
If physical & chemical barrier
is broken down by:
•trauma
•as result of infection on surface
invading microorganisms can
enter body, blood stream &
lymphatic system.
Inside the body, pathogens can find
a niche in body tissue to multiply
and form a colony.
Normally our bodies are
fit enough to fight an
infection with all the parts
of our immune system.
Sometimes we need help
fighting infection.
•Antibiotics are chemicals developed
to help us in the fight infection.
•Antibiotics reduce risk of tissue
damage while immune system
fights off infection.
•They also reduce risk of death
if immune system is unsuccessful.
Antibiotics are not
essential and we
would often win
without them.
The argument has been made that
antibiotics are over prescribed.
For minor infections
with low risks we
should wait for the
body's own defenses.
There is a protective effect of
normal microorganisms which live
on skin & mucosal membranes.
These usually prevent other more
dangerous bugs from spreading.
•If for example you have a course
of antibiotics for an infection…
•as well as killing off the harmful
bacteria causing the infection,
•some of the good resident
microbes will die, leaving an
opportunity for others to grow.
Pathogens which grow under
these conditions are called
opportunistic pathogens.
A good example of an opportunistic
infection: thrush or candida
Note white fungal patches under tongue
This yeast-like fungus normally
lives on skin, in gut & vagina in
small, well-controlled numbers.
After using antibiotics, fungi get a
chance to multiply.
Hypersensitivity
Disorders
Contact dermatitis
http://www-medlib.med.utah.edu/WebPath/IMMHTML/IMM029.html
Hypersensitivity-contact
dermatitis
http://tray.dermatology.uiowa.edu/ImageBase.html
Photosensitive
dermatitis
http://tray.dermatology.uiowa.edu/ImageBase.html
Skin reaction to
insect bite.
Brown Recluse
Spider
Poison Ivy Dermatitis
http://health.discovery.com/diseasesandcond/encyclopedia/132.html
Hives
Allergic Welts
http://www.dermatest.de/PB/Publikationen/PBEN/Allergic_skin_reactions/body_allergic_skin_reactions.html
Allergic Rhinitis
http://www.emedicine.com/PED/topic2560.htm
allergic rhinitis nose rub
“allergic shiners” as result of
allergic rhinitis
http://www.emedicine.com/PED/topic2560.htm
Nasal Polyp
http://www.ghorayeb.com/NasalPolyps.html
http://www.ghorayeb.com/NasalPolyps.html
Anaphalaxis
•Hypersensitivity reaction in
which antibody on mast cells
quickly reacts with an antigen.
•Mast cells release histamine &
other mediators that lead to
edema.
Some causes of a
hypersensitivity reaction:
acute laryngeal edema due to
anaphylactic reaction to penicillin
http://www-medlib.med.utah.edu/WebPath/IMMHTML/IMM030.html
Autoimmune
Disorders
patient with scleroderma
note taunt skin and scaring at
corners of mouth
http://www-medlib.med.utah.edu/WebPath/IMMHTML/IMM024.html
Sclerodactyly as result of
scleroderma
http://www.dermis.net/doia/diagnose.asp?zugr=d&lang=e&diagnr=710110&topic=t
Lupus
“butterfly
rash”
http://www-medlib.med.utah.edu/WebPath/IMMHTML/IMM009.html
Another lupus “butterfly rash”
Also called “malar rash”
Myasthenia
gravis
Three different
serial pictures
demonstrate
fatigue of eyelid
muscles as patient
keeps looking up.
http://www.methodisthealth.com/health/nervsystem/Myasgrav.htm
Rheumatoid arthritis
http://www-medlib.med.utah.edu/WebPath/ORGAN.html#1
X-ray rheumatoid arthritis
http://www.vh.org/adult/provider/radiology/icmrad/skeletal/Parts/RAHands.html
Jaundice of sclera from auto immune
disease -- primary biliary cirrhosis
Immunodeficiency
Disorders
Kaposi’s Sarcoma-roof of mouth
http://www.maxillofacialcenter.com/BondBook/softtissue/kaposi.html
Kaposi’s Sarcoma
http://pathsrvr.rockford.uic.edu/inet/Immune%20Disorders/Immune%20Disorders%20Station%203.htm
Summary
Immune system consists of:
•Thymus gland
•Bone marrow
•Lymph nodes
•Spleen
•Liver
•Tonsils
•lymphocytes
Malfunctioning or compromised
immune systems:
•Leave the body with weakened
defenses against pathogens and
opportunistic microbes
Primary disorders of immune
system are categorized as:
1.Hypersensitivity disorders
(allergy, autoimmune)
2.Immune deficiency disorders
(congenital immunodeficiency,
AIDS)
•Treatment for immune
disorders varies
•Some immune disorders are
mild while others are severe
and require long-term therapy