First line of defense

1
First line of defense (non-specific barriers)
physical and chemical barriers that prevent
pathogens from entering (skin, mucus, acids in
the stomach, etc.) This barrier is non-specific
because it will exist no-matter-what.
2

• Second line of defense
• (non-specific white blood cells) leukocytes are
  white blood cells. They are non-specific because
  they will react to any foreign invader.
• INFLAMMATION Damaged tissues leukocytes cause
  blood vessels to dilate and the area becomes RED.
  Fluid builds up, causing SWELLING and PAIN.
• Phagocytes and monocytes eat foreign invaders.

Granulocytes
Neutrophil Phagocytes (engulf and destroy bacteria)
Eosinophil Kills parasitic worms, destroys antigen-antibody complexes
Basinophil Releases heparin (anti-coagulant) and histamine, which prevents inflammation.
Agranulocytes
Lymphocyte Involved in the immune response.Includes B cells and T cells.
Monocyte Phagocytosis Monocytes are the chief phagocytes. They circulate in the blood for 12 days before entering body tissues to become macrophages.
3
Third line of defense (specific
antigens/antibodies) 1. The pathogen or foreign
invader has ANTIGENS on the surface of its
structure. 2. White blood cells called
lymphocytes recognize a foreign invader because
of its ANTIGENS and will cause our B cells (types
of lymphocytes, white blood cells) to begin to
make proteins called ANTIBODIES. 3. ANTIBODIES
have a special molecular form that allows them to
match ANTIGENS like a puzzle piece. 4. Once
attached, the invader can be destroyed! Some B
cells can remember an antigen and produce
antibodies quicker next time!
4
Pathogen infects human. This pathogen contains
___________ that mark it as an invader.
A white blood cell (phagocyte) recognizes the
pathogen as an invader and engulfs it through
________________.
antigens
phagocytosis
T
activates
The phagocyte ____________ Helper T cells.
The phagocyte now displays the antigen from the
_______________.
pathogen
B
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Helper T cells activate B cells which then
produce _______________.
antibodies
These antibodies attach to the pathogen and
signal for them to be ___________.
destroyed
5
VOCABULARY Antigen marker on pathogens that
signal for the production of antibodies. Antibodi
es proteins that are found in the blood that
detect and destroy invaders. Vaccine a
weakened or dead pathogen that is injected into a
organism to stimulate the immune system and the
production of antibodies. Pathogen Any
bacteria or virus that can cause disease.
6
First line of defense (non-specific barriers)
7
Second line of defense (non-specific white blood
cells) 1. 2.
Granulocytes
Neutrophil Phagocytes (engulf and destroy bacteria)
Eosinophil Kills parasitic worms, destroys antigen-antibody complexes
Basinophil Releases heparin (anti-coagulant) and histamine, which prevents inflammation.
Agranulocytes
Lymphocyte Involved in the immune response.Includes B cells and T cells.
Monocyte Phagocytosis Monocytes are the chief phagocytes. They circulate in the blood for 12 days before entering body tissues to become macrophages.
8
Third line of defense (specific
antigens/antibodies) 1. The pathogen or foreign
invader has ANTIGENS on the surface of its
structure. 2. White blood cells called
lymphocytes recognize a foreign invader because
of its ANTIGENS and will cause our B cells (types
of lymphocytes, white blood cells) to begin to
make proteins called ANTIBODIES. 3. ANTIBODIES
have a special molecular form that allows them to
match ANTIGENS like a puzzle piece. 4. Once
attached, the invader can be destroyed! Some B
cells can remember an antigen and produce
antibodies quicker next time!
9
THIRD LINE OF DEFENSE SPECIFIC IMMUNE RESPONSE
Pathogen infects human. This pathogen contains
___________ that mark it as an invader.
A white blood cell (phagocyte) recognizes the
pathogen as an invader and engulfs it through
_________________.
T
The phagocyte _________ Helper T cells.
The phagocyte now displays the antigen from the
______________.
Helper T cells activate B cells which then
produce _________________.
These antibodies attach to the pathogen and
signal for them to be _________.
Antigen__________________________________________
________ ________________________________________
_________ Antibody ______________________________
___________________ _____________________________
____________________ Vaccine ___________________
_______________________________ _________________
________________________________ Pathogen
_________________________________________________