12.1 Notes – Causes of
Communicable Diseases
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disease – any condition that interferes with the
proper function of the body or mind
communicable disease – (contagious) a
disease that can be spread to a person from
another person, an animal, or an object
noncommunicable disease – not contagious
germs – organisms that are so small that the
can be seen only through a microscope
Are all germs bad for you?
– no
12.1 Notes – Causes of
Communicable Diseases
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pathogens – the germs that are responsible
for causing disease
infection – a condition that occurs when
pathogens enter the body, multiply, and
damage body cells
4 types of pathogens:
12.1 Notes – Causes of
Communicable Diseases
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4 types of pathogens:
1. viruses – the smallest and simplest diseasecausing organism
2. bacteria – tiny one-celled organisms that live
nearly everywhere
3. fungi – primitive life-forms, such as molds or
yeast, that cannot make their own food (athlete’s
foot)
4. protozoa – one-celled organisms that have a more
complex structure than bacteria
12.1 Notes – Causes of
Communicable Diseases
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2 microscopic pathogens:
1. viruses
2. bacteria
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2 macroscopic pathogens:
1. fungi
2. protozoa
12.1 Notes – Causes of
Communicable Diseases
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Pathogens and the diseases they cause:
– Viruses:
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AIDS, chicken pox, colds, hepatitis, herpes, influenza,
measles, mononucleosis, mumps, polio, rabies,
smallpox, viral pneumonia
– Bacteria:
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Bacterial pneumonia, diphtheria, most foodborne
illnesses, gonorrhea, Lyme disease, pinkeye, step
throat, tuberculosis
– Fungi:
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Athlete’s foot, ringworm
– Protozoa:
12.1 Notes – Causes of
Communicable Diseases
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How can pathogens spread?
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Getting bitten by an infected animal
Sexual contact
Sharing blood
Drinking or eating something after someone is
sick
– E-coli, food poisoning
– Kissing, touching
– Sneezing, coughing