Download endocrine system - Crestwood Local Schools

• Protection
against
infection &
disease
SELF vs. NONSELF
• Self
• Body
recognizes
molecules
(MHC proteins)
in plasma
membrane as a
label of “self”
• Non-self
• Unfamiliar
antigens are
not recognized
and stimulate
reaction from
immune system
Second Line of
Defense
•
•
Non-specific
Defensive cells
•
•
•
•
Proteins
•
•
•
Phagocytes
(Neutrophils &
Macrophages)
Eosinophils
Natural Killer
Cells
Interferons
Complement
system
Inflammatory
Response
Inflammatory Response
•
•
•
•
Non-specific!
Small, mobile connective
tissue cells called Mast
Cells release histamines in
response to chemicals
from damaged cells,
causing “inflamed” look
beneath skin
Histamines make blood
vessels dilate, causing
redness, swelling, heat &
pain
If infection is severe or
spreads, fever & stronger
immune response can
result
Humoral (Antibody-Mediated)
Immunity
•
Primarily defends against
extracellular pathogens or toxins
B-cell
Bacteria
with
Antigens on
Surface
Bacterial antigens also
stimulate B-cells
T-cell
A large
phagocyte called
a macrophage
engulfs a
bacterium
Macrophage
T-cell binds to
activated
macrophage
Helper T-cell assists
the activated B-cell
to develop into an
antibody-producing
plasma cell
Activated B-cells
proliferate to produce
clones of memory cells
Circulating antibodies
bind to bacterial
antigens, helping other
immune cells to identify
and destroy bacteria
T-cell, activated by
macrophage,
becomes a Helper Tcell
Plasma cell produces
large amounts of
antibody proteins,
released into the
bloodstream
Antigens are displayed on
surface of macrophage
after digestion of
bacterium
T-cell binds to
activated macrophage
Helper T-cell
Helper T-cell
activates Killer Tcells and B-cells
T-cell
Antigens are
displayed on surface
of macrophage
Killer T-cell
Infected Cell
T-cell, activated by
macrophage becomes
a Helper T-cell
Macrophage
Killer T-cells bind to
infected cells, disrupting
their cell membranes and
destroying them
Artificial Immunity
•
•
Antibodies are introduced
into the body by nonnatural processes (i.e. injections)
Requires intentional actions
ACTIVE
•
NATURAL
•
•
ARTIFICIAL
•
Due to a specific
immune response in
the body, a survivor
of a disease is
permanently immune
to a recurrence of
that disease.
Example: Measles
Vaccination for a
disease causes a
specific immune
response in the
body, resulting in
permanent immunity
to that disease.
Example: Polio
PASSIVE
•
Newborn infant gets
antibodies from its
mother, providing
temporary immunity
to diseases that the
mother had an active
immunity to.
•
Injection of
antibodies for a
disease (produced by
another source)
provides temporary
immunity to the
disease
Example: Rabies
•
ACTIVE
•
NATURAL
•
•
ARTIFICIAL
•
Due to a specific
immune response in
the body, a survivor
of a disease is
permanently immune
to a recurrence of
that disease.
Example: Measles
Vaccination for a
disease causes a
specific immune
response in the
body, resulting in
permanent immunity
to that disease.
Example: Polio
PASSIVE
•
Newborn infant gets
antibodies from its
mother, providing
temporary immunity
to diseases that the
mother had an active
immunity to.
•
Injection of
antibodies for a
disease (produced by
another source)
provides temporary
immunity to the
disease
Example: Rabies
•
Antigen (1st exposure)
Engulfed by
Free antigens
directly activate
Antigens displayed by
infected cells activate
Macrophage
Stimulates
B-cell
Stimulates
Helper T-cell
Stimulates
Cytotoxic
T-cells
Gives rise to
Gives rise to
Gives rise to
Memory
Helper T-cell
Stimulates
Stimulates
Antigen (2nd exposure)
Plasma
cells
Antibodies
Memory
B-cells
Stimulates
HUMORAL IMMUNE
RESPONSE
Memory
T-cells
CELL-MEDIATED
IMMUNE RESPONSE
Active
Cytotoxic
T-cells
Attack cells with
this antigen
Blood or Tissue
Rejection
– Antigens present on
transfused blood or
transplanted tissues or
organs stimulate an
immune response that
causes those cells to be
targeted by immune cells
– Graft-Versus-Host
Disease
– Condition occasionally
resulting from
transplanted bone
marrow
– Transplanted bone
marrow (source of
immune cells) does not
recognize and
therefore attacks body
tissues and organs
– Rejections can be life-
threatening
Allergies & Asthma
– Allergies
– Antigens from allergens
bind to Mast Cells &
trigger inflammatory
response
– Mast Cells release
histamines, which
cause sneezing, runny
nose & eyes, and other
irritations
– Asthma
– Allergens, irritations, or
stressful activities
stimulate an
inflammatory response
from the immune
system
– Inflammatory response
causes swelling and
constriction of the
airways, making it
difficult to breathe
Immune Deficiency Diseases
•
Primary
•
Secondary
– A genetic (inherited) condition that
compromises the immune system’s
ability to fight off infection
– Example: Severe Combined
Immunodeficiency
• Aka “Bubble Boy” disease
• Genetic mutation disables immune
system and leaves child susceptible
to any infection
• Bone marrow transplant is the only
known cure
• Without treatment, patients die in
early childhood
– Aka “Acquired”
– Compromised immune function due to
infection or disease
– Not genetic
– Example: HIV/AIDS
What is a microbe?
– Tiny!
– Cannot be seen with
the naked eye.
– Domain Archaea
– Domain Eubacteria
– Domain Eukarya
–
–
–
–
Protists
Fungi
Plants
Animals
Shapes
•
•
•
Cocci: sphere-shaped
Bacilli: rod-shaped
Spirilla: spiral-shaped
Autotrophs
• Photoautotrophic
•
•
•
Photosynthetic (energy from sun & carbon
from CO2)
Often found on surface of water
Cyanobacteria (formerly known as “bluegreen algae”)
•
•
•
Found in fresh and salt water and on land
Some can survive in extreme environments
Often the first species to recolonize
natural disaster sites (i.e. volcanic
eruption)
• Chemoautotrophic
•
•
•
Obtain energy directly from inorganic
molecules, such as iron-, sulfur- or
nitrogen-based compounds
Basis of the only known ecosystems that
are not dependent on sunlight
Example – Deep ocean vents
Bacteria as Pathogens
– Bacteria can cause disease in two ways
– Directly infecting body tissues
(i.e. H. pylori)
– Producing toxins
(i.e. Clostridium botulinum)
Terminology
– Disease
– Any change, other than an injury,
which interferes with the normal
functioning of the body
– Pathogen
– Disease-causing microorganism
– Infection
– Disease caused by a pathogen
Specificity
– Viruses only infect particular cell
types
– May infect multiple species
– May only infect one
particular species
– May only infect one cell type
within that species
Characteristics
– Non-cellular particle made up
of genetic material inside
a protein coat
– Obligate intracellular parasite –
activities associated with life
only occur when virus invades
a host organism’s cell
– ARE VIRUSES ALIVE????
Structure & Shape
•
•
•
Nucleic acid core composed
of either DNA or RNA
Protein coat (capsid)
surrounds genetic material
Viruses come in many
shapes & sizes
Entry
Attachment
Replication
Assembly
Lysis
Prion Diseases
Creutzfeldt-Jakob disease
– “Mad Cow” disease
– Infection from eating
contaminated food
Fatal Familial Insomnia
– Autosomal dominant
– Onset between 35 & 60
Kuru
– Infection caused by eating
infected human brain tissue
– Found almost exclusively in New
Guinea among people who
practice a form of cannibalism as
part of a funeral ritual.
Gerstmann-Straussler
syndrome
– Almost always inherited
(autosomal dominant)
– Onset between 20 & 55
Prion Diseases
Creutzfeldt-Jakob disease
– “Mad Cow” disease
– Infection from eating
contaminated food
Fatal Familial Insomnia
– Autosomal dominant
– Onset between 35 & 60
Kuru
– Infection caused by eating
infected human brain tissue
– Found almost exclusively in New
Guinea among people who
practice a form of cannibalism as
part of a funeral ritual.
Gerstmann-Straussler
syndrome
– Almost always inherited Normal
(autosomal dominant)
– Onset between 20 & 55 Protein
Fungi
• Single or multicellular
• Eukaryotic
• Cause disease by
“digesting” host cells
Parasitic Protists
– Often have complex life-cycles involving more than
one host
– Examples:
– Trypanosoma (African Sleeping Sickness)
– Giardia (intestinal parasite)
– Entamoeba histolytica (Amoebic Dysentery)
– Certain diatoms (“Red tides”)
Parasitic Protists
– Often have complex life-cycles involving more than
one host
– Examples:
– Trypanosoma (African Sleeping Sickness)
– Giardia (intestinal parasite)
– Entamoeba histolytica (Amoebic Dysentery)
– Certain diatoms (“Red tides”)
– Toxoplasma gondii (toxoplasmosis)
– Plasmodium falciparum (malaria)
Flatworms


Flukes (parasitic)
Tapeworms (parasitic)
Infective cyst
forms in flea
Dog becomes
infested with fleas
Adult flea
eaten by
dog during
grooming
Tapeworm eggs
eaten by flea larvae
Tapeworm
segments passed
in dog’s feces.
Head “hooks”
Tapeworm
eggs
Ingestion
Sucker
Defecation
Cow host
Human
host
Adult tapeworm
in human intestine
Ingestion
Beef containing
tapeworm cysts
Larvae migrate
to muscle tissue
and form cysts
Flatworms


Flukes (parasitic)
Tapeworms (parasitic)
Nematodes




Ascarid worms (heartworm)
Hookworms
Filarial worms
Pinworms
Heartworm
Pinworm
Eggs are ingested
Eggs
contaminate
fingers
Larvae hatch in
small intestine
Eggs embryonate Larvae migrate to
on perianum
colon & mature
Larvae enter
lungs & cause
coughing
Larvae penetrate
skin & enter
bloodstream
Gravid adults
migrate out of
anus & lay eggs
Pinworms are the most common worm infection in the
U.S. (over 40 million cases per year—usually in children).
Larvae
migrate
to grass
Larvae hatch &
develop in soil
Larvae are
coughed up
& swallowed
Larvae reach
small intestine,
mature, & start
feeding
Eggs are
passed in
feces and
enter soil
Flatworms


Flukes (parasitic)
Tapeworms (parasitic)
Nematodes




Ascarid worms (heartworm)
Hookworms
Pinworms
Filarial worms
Segmented worms

Leeches