Transcript How does the immune system protect the body against disease?

TOPIC: Immunity
AIM: How does the
immune system protect
the body against
disease?
Immune
system
• Protects the body
against disease
What is a • Materials that cause
pathogen? disease (germs)
• Microorganisms
• Bacteria, viruses,
parasites, fungi…
•
Proteins
found
on
Antigen
the “bad guy or
substances” that are
foreign to your body.
• Bad guys =
pathogens,
microorganisms,
allergens etc.
The Body’s Lines of
Defense
st
1
line • Physical barriers 
• keep pathogens out of
the body
• skin,
• mucus,
• cilia,
• sweat,
• tears,
• saliva,
• digestive enzymes
•
1.
Inflammatory
response:
2nd
• WBC’s destroy pathogens
line
Antibodies • Proteins that
(3rd line)
help destroy
pathogens
• Made bc of an
immune response
• Attach to antigen & slow it
down so WBC’s can destroy
them
How are • 2 types of WBC’s
antibodies • T cells tell B cells to
make antibodies
made?
• 1. Infectious =
2
types of • pathogens spread to
another person
disease
• Ex: cold, flu, AIDS
• 2. Noninfectious = cannot be
spread
• (not caused by pathogen)
• Ex: Diabetes, cancer
AIDS
• Acquired Immune
Deficiency
Syndrome
• Infectious
disease
• Caused by HIV (Human
immunodeficiency virus)
Damages immune system by
destroying T cells
(body can’t fight off pathogens)
How is
HIV
transmitted?
1. Contact with
infected blood
2. Sharing
intravenous
needles
3. Sexual contact
4. Motherfetus
Allergies • An immune response or
reaction to substances
you are allergic
(sensitive) to
• Allergen = what you are
allergic to
• (pollen, dust, etc)
• Histamines produced
(chemicals released by cells that
cause symptoms)
Review:
1. What is a pathogen?
2. Explain what makes up your body’s first
line of defense.
3. How are antibodies produced?
4. How are infectious diseases different
from noninfectious diseases?
5. How does HIV affect the body?
6. What is an allergy?