Transcript The Immune System

The Immune System
Lines of Defense
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1. Skin and mucous membranes
2.Celia in respiratory system
3.Fever
4.Mechanical actions (coughing,sneezing,etc.)
5.White blood cells (lymphocytes)
6.Interferon (fights viruses and cancers)
3 Factors to remember
• 1. Memory- response is quicker when the
same antigen is introduced a second time
• 2. Specificity-Immunity is specific to 1 antigen.
There are approximately 1 billion lymphocytes
specific for approximately 1 million different
antigens.
• 3. Recognition of non-self
Phagocytes
• These are feeding cells.
• Macrophages are considered the “foot soldiers”
of the immune system
• Duties of the macrophage:
• A large feeding cell that can suddenly increase its
area in order to surround and enclose an enemy.
• Shoots out a kind of sticky cytoplasm
(pseudopods) which adhere to bacteria in order
to pull in its prey.
• Vacuums dead cells in system during an
infection
• Releases interleuken 1 which alarms t cells
• Produces growth factors which help to heal
tissue during infections
• Produces enzymes which annihilate bacteria
Macrophage
Virus And Bacteria
Immune System on Alert
Cancer cell attacked by CD8 (Killer) cell
T cells
Killer t cell
T-cells attacking a cancer cell
Immunoglobulins
• Antibodies belong to a family of large molecules called
Immunoglobulins
• IgG—coats microbes-crosses placenta
• IgM-effective in killing bacteria—usually in blood
stream
• IgE-protect against parasites-responsible for allergies
• IgA-concentrates in body fluids-tears, respiratory tract,
digestive tract-guards entrances to the body-found in
colustrum
• IgD-in umbilical cord
Anaphylactic Allergic Reaction