Transcript The Immune System

The Immune System
Pathogens
• Defined: microorganisms
that cause disease
– Viruses: turn cells into
virus making factories
Pathogens
• Defined: microorganisms
that cause disease
– Viruses: turn cells into
virus making factories
– Bacteria: prokaryotes
can release toxic
chemicals
Pathogens
• Defined: microorganisms
that cause disease
– Viruses: turn cells into
virus making factories
– Bacteria: prokaryotes
can release toxic
chemicals
– Fungi: pierce cells and
absorb the nutrients
Pathogens
• Defined: microorganisms
that cause disease
– Viruses: turn cells into
virus making factories
– Bacteria: prokaryotes
can release toxic
chemicals
– Fungi: pierce cells and
absorb the nutrients
– Protozoans: single celled
protista (eukaryotes)
Plasmodium causes malaria
Pathogens
• Defined: microorganisms
that cause disease
– Viruses: turn cells into
virus making factories
– Bacteria: prokaryotes
can release toxic
chemicals
– Fungi: pierce cells and
absorb the nutrients
– Protozoans: single celled
protista (eukaryotes)
– Parasites: grow and feed
on a host
tapeworms
Transmission
• Some carried by wind, water,
direct contact, indirect contact…
Two of the
dirtiest things
you touch on a
daily basis are…
Transmission
• Some carried by wind, water,
direct contact, indirect contact…
• Vectors: organism that carries a
pathogen
Examples:
1) Malaria disease
• Cause: Plasmodium protozoa
• Vector: Mosquitos
Transmission
• Some carried by wind, water,
direct contact, indirect contact…
• Vectors: organism that carries a
pathogen
Examples:
1) Malaria disease
• Cause: Plasmodium protozoa
• Vector: Mosquitos
2) Bubonic Plague
• Cause: Bacterium Yersinia pestis
• Vector: Fleas
Transmission
• Some carried by wind, water,
direct contact, indirect contact…
• Vectors: organism that carries a
pathogen
Examples:
1) Malaria disease
• Cause: Plasmodium protozoa
• Vector: Mosquitos
2) Bubonic Plague
• Cause: Bacterium Yersinia pestis
• Vector: Fleas
3) Rocky Mtn. Spotted Fever
• Cause: Bacteria Rickettsia
• Vector: Ticks
The Skin
• 1st line of defense: physical barrier
• Oils & sweat destroy some pathogens
– Some pathogens burst…some shrivel
bacteria
bacteria
Skin
Commonly inhaled:
Viruses
Bacteria
Pollen
Dirt
Dust
Fungal spores
fungus
bacterium
virus
Mucus Membranes
• Coat the openings
of the body
– Nose, mouth, ears,
eyes, genitals, anus
• Lined with cilia &
sticky fluids to trap
pathogens
Defense Proteins
Lymphocyte
Y
Y
Y
antigen
• Antibodies
– Created & released by lymphocytes
– Attach (like handcuffs) to antigens of invader
Defense Proteins
• Antibodies
– Created & released by
lymphocytes
– Attach (like handcuffs) to
antigens of invaders
– How do they kill?
1) Causes pathogens to
clump
Defense Proteins
• Antibodies
– Created & released by
lymphocytes
– Attach (like handcuffs) to
antigens of invaders
Y
Y
Y
Y
Y
Y
Bacterium
Y
Y
– How do they kill?
1) Causes pathogens to
clump
2) Weakens the cell
membrane of the
pathogen
antibody
Defense Proteins
• Interferon
1) Cell becomes
infected by
virus
2) Infected cell
sends interferon
to healthy
neighbors
3) Interferon
causes healthy
cell to create
defense
enzymes
4) Healthy cell
able to fight
virus
virus
Virus
RNA
New virus
New virus
New virus
New virus
Interferon
New virus
Infected!
Not Infected!
White Blood Cells
• Job: Search & destroy
White Blood Cells
and bacterium
The
digested
is placed
into
harmless
inside
a lysosome…
fragments.
• Job: Search & destroy
• Type 1: Phagocytes
– surround & engulf invaders by phagocytosis
Blood
stream
Cool Phagocyte Video Clip
YouTube Clip: Types of White Blood Cells (phagocytes) from the BBC
White Blood Cells
Y B cell Y
LymphoY cyte Y
phagocyte
Blood
Stream
Y B cell Y
LymphoY cyte Y
• Job: Search & destroy
• Type 1: Phagocytes
– surround & engulf invaders by phagocytosis
• Type 2: Lymphocytes
– create antibodies & destroy infected body cells
Cool Lymphocyte video clip
YouTube Clip: Types of White Blood Cells (lymphocytes) from the BBC
Vaccination
• Prevents infections (not a
cure)
• Vaccination process
1) Weakened pathogen is
injected
2) Immune system
produces…
1955: Jonas Salk created a vaccine for Polio
Vaccination
Memory
Dead virus
B cell
YYB cellYY
Y
Y Lympho- Y
YY cyte YY
Memory
B cell
Dead virus
Dead virus
• Prevents infections (not a
cure)
• Vaccination process
1) Weakened pathogen is
injected
2) Immune system
produces…
a) Antibodies to fight
the weakened
pathogen
b) Memory cells for
future infections
• Goal: Memory cells and
antibodies kept for life
• 30 years later: What
happens if you re-catch the
living virus?
The Celebrity Effect: Jenny McCarthy
claims vaccines cause autism.
Vaccines Don't Cause Autism: Healthcare Triage
60 Minutes Australia - Vaccine Debate Story
Anti-Vaccination Church Has Measles Outbreak
Review
1) Which part of our immune system coats the openings of
the body?
2) How do lymphocytes differ from phagocytes?
3) What are antibodies and how do they help keep us from
harm?
4) Which pathogen…
absorbs nutrients from living tissue?
are prokaryotic?
5) Which illness is spread by mice?
6) What is the vector of malaria?
7) Why are people given dead/weakened pathogens?