Immune Response, Toxins, &
Nutrition
Immune Response to
Microorganisms
Immune system – the body system that
protects against pathogens and cancer
Immunity – the ability to resist disease
The immune system has 3 lines of defense:
Immune Response
1st line of defense (nonspecific): skin, ciliated cells,
mucus membranes – act as barriers and traps
Immune Response
2nd line of defense (nonspecific): increased body temperature
(fever) to create conditions unsuitable for pathogen
growth; increased blood flow to injured or infected site
resulting in inflammation; blood brings white blood cells
called macrophages that engulf and kill pathogens
Immune Response
3rd line of defense (specific): macrophages activate helper T
cells that (1) activate other T cells that destroy infected
cells and (2) activate B-cells to make antibodies;
antibodies attach to pathogens, clumps them, and signals
them for destruction.
Passive vs. Active Immunity
Active Immunity – body’s own immune
response is activated and produces
antibodies; occurs when a pathogen or a
vaccination is introduced into the body;
long-term effect; once you get exposed to
pathogen, you retain those antibodies for
awhile, explaining why some diseases are
only contracted once in a lifetime
Active Immunity
Memory B
cells keep
antibodies “on
file” in case of
future
exposure to
antigen
Passive vs. Active Immunity
Passive Immunity – antibodies are introduced
into the body (not a result of immune
system response); example – mother
transfers her immunity to infant during
breast-feeding; effects are short-term
Vaccines
• Made from weakened pathogens, pathogen
parts, dead pathogens
• Injections, nasal sprays, ingested
• Causes body to make antibodies that can be
used if it is exposed to the “real deal”; will
shorten or prevent illness
• There are risk factors – allergic reactions,
actually getting disease from vaccine, etc.
Vaccines now
available for:
Toxins
Effects of Environmental Toxins
Toxin – poisonous substance that can cause
disease
– Symptoms depend on dose, how long you’ve
been exposed, the way it got in the body, and
body response.
Effects of Environmental Toxins
1. Mercury
– Sensory impairment (vision, hearing, speech), lack of
coordination, disturbance in sensations (pins and
needles), muscle weakness, skin rash, mood swings,
memory loss, mental disturbance
– Damage to central nervous system, liver, digestive
tract, kidneys, prolonged exposure leads to brain
damage and death
– Major sources – ingestion of contaminated food
(mainly fish) and water, air pollution, improper use of
items such as thermometers and fluorescent light
bulbs
Mercury
From 1932 to 1968, the Chisso
Corp. dumped nearly 27 tons of
mercury waste into Minamata
bay, Japan. In the mid-1950’s, a
strange disease emerged that
seemed to affect cats, birds, and
people.
http://science.education.nih.gov/supplements/nih2/chemi
cals/activities/lesson5.htm or
http://aileenarchive.or.jp/minamata_en/slides/swf.html
Effects of Environmental Toxins
2. Lead
– Major sources – lead paint (1978), toys, lead
bullets, sinkers, plumbing, air (when we used
leaded gas), pewter
– Symptoms:
• Child: irritability, weight loss, sluggishness,
abdominal pain
• Adult: pain/tingling in the extremities, muscle
weakness, headache, abdominal pain, memory loss,
mood disorders, reduced sperm count, abnormal
sperm
Lead
Lead
Paint
chips
Nutrition
Nutrition
1. Good Nutrition – can maintain good health and
prevent disease
–
Nutrients are substances the body needs to obtain
energy and build and replace tissue
•
•
•
•
•
–
Carbohydrates – energy
Fats – store energy, insulation, building cell membranes
Proteins – chemical reactions, body structure, traits
Vitamins – naturally occurs in plant and animals; help body
with specific functions
Minerals – not made by living things (ex. Calcium, iron)
Good nutrition is a balance of all of the above
Nutrition
2. Bad Nutrition – can
lead to:
– Obesity – the wrong
amounts of
sugars/carbohydrates
and fats coupled with
lack of or too little
exercise; also has
genetic component;
can lead to other
complications such as
diabetes
Nutrition
– Malnutrition – an
overall deficiency of
most or all the
nutrients; can lead to
other complications
including decreased
immunity
Malnourished
child with
dysentery
Nutrition
– Specific deficiencies – not
enough of certain vitamins
and minerals can lead to
specific health problems
Examples:
Scurvy – deficiency of
Vitamin C; causes
inflammation of the
tongue, spongy gums, blue
and black spots on skin,
sunken eyes, pallor,
corkscrew hair,
nosebleeds; was common
among sailors
Nutrition
Goiters – deficiency of
iodine; causes
swelling of the thyroid
gland (in your neck),
tight feeling in your
throat, coughing,
trouble swallowing
and breathing; not a
problem in U.S. since
iodized salt.
Nutrition
Osteoporosis – disease
caused by lack of enough
calcium in the diet over
many years; causes brittle
bones, and
hunched/stooped over
appearance.
For more about vitamin & mineral
needs/deficiencies:
http://www.changingshape.com/
resources/references/vmchart.as
p