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
that can release toxic
chemicals
YouTube clip: Bacteria growth
Pathogens
• Defined: microorganisms
that cause disease
– Viruses: turn cells into
virus making factories
– Bacteria: prokaryotes
that 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
that can release toxic
chemicals
– Fungi: pierce cells and
absorb the nutrients
– Protozoans: single cells
protista (eukaryotes)
Plasmodium causes malaria
Pathogens
• Defined: microorganisms
that cause disease
– Viruses: turn cells into
virus making factories
– Bacteria: prokaryotes
that can release toxic
chemicals
– Fungi: pierce cells and
absorb the nutrients
– Protozoans: single cells
protista (eukaryotes)
YouTube clip: Monster’s
Inside Me (malaria)
Pathogens
• Defined: microorganisms
that cause disease
– Viruses: turn cells into
virus making factories
– Bacteria: prokaryotes
that can release toxic
chemicals
– Fungi: pierce cells and
absorb the nutrients
– Protozoans: single cells
protista (eukaryotes)
– Parasites: grow and feed
on a host
tapeworms
Transmission
• Some carried by wind,
water, direct contact,
indirect contact…
• Some carried by vectors
– Vector: object that
carries a pathogen
Examples:
1) Malaria – mosquitos
carry the protozoan
2) Black Death – carried by
flea’s of mice
3) West Nile Virus – carried
by birds, but spread by
mosquitoes
The Skin
• 1st line of defense: physical barrier
• Oils & sweat destroy some pathogens
– Some pathogens burst…some shrivel
bacteria
bacteria
Skin
Mucus Membranes
• Coat the openings of the body
– Nose, mouth, ears, eyes, genitals, anus
• Lined with cilia & sticky fluids to trap pathogens
YouTube Clip: Types of
White Blood Cells
(phagocytes) from the BBC
White Blood Cells
• Job: Search & destroy
YouTube Clip: Types of
White Blood Cells
(lymphocytes) from the BBC
YouTube Clip: Types of
White Blood Cells
(phagocytes) from the BBC
White Blood Cells
• Job: Search & destroy
• Type 1: Phagocytes
– surround & engulf invaders by phagocytosis
YouTube Clip: Types of
White Blood Cells
(lymphocytes) from the BBC
YouTube Clip: Types of
White Blood Cells
(phagocytes) from the BBC
White Blood Cells
• Job: Search & destroy
• Type 1: Phagocytes
– surround & engulf invaders by phagocytosis
• Type 2: Lymphocytes
– T cells: destroy infected body cells
– B cells: create antibodies
YouTube Clip: Types of
White Blood Cells
(lymphocytes) from the BBC
Blood
stream
Defense Proteins
• Antibodies
– Created & released by B cells
– Attach to antigens found on
surface of invaders
antibody
Y
Y
BY
cell
Defense Proteins
• Antibodies
– Created & released by B cells
– Attach to antigens found on
surface of invaders
– How they help:
1) Bind to antigens of
pathogen (like handcuffs)
– Causes pathogens to clump
– Easy targets for phagocytes
2) Weakens the cell membrane
of pathogen
– Causes them to burst
B CELLS MAKE ANTIBODIES
ANTIBODIES ATTACH TO ANTIGENS OF THE PATHOGEN
Y
Y
Y
Y Y
Y
YY
YY
Y
Y
Blood
Stream
Y
Y
Y Y
Y
Y
Y
phagocyte
Y
Y
Y
ANTIBODIES CAUSE THE PATHOGENS TO CLUMP TOGETHER
PHAGOCYTE DESTROYS PATHOGENS
Y
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!
Vaccination
• Prevents infections (not
a cure)
• Vaccination process
– Weakened pathogen
is injected
– Immune system
produces…
• Antibodies to fight
the weakened
pathogen
• Memory cells for
future infections
• Goal: Speed up immune
response if you
encounter the actual
virus
Kobe Kuiz
1) Which part of our immune system coats the openings of
the body?
2) Name and describe the two types of lymphocytes.
3) What are antibodies and how do they help keep us from
harm?
4) Summarize how vaccines are created.
5) Which pathogen…
absorbs nutrients from living tissue?
are prokaryotic?
6) Which illness is spread by mice?
7) What is the vector of malaria?