Corrie DiSalvoDiana DuqueKristin HopkinsLizbeth LondonoMarcela Morado

Chapter 28 Lessons 1 & 3 7th Grade

Infectious Diseases

Diseases caused by the growth of pathogenic organisms in the body

Bacteria• A single-celled microorganism

• Abundant in air, soil, and water

• Harmful

• Rapid Multiplication

Viruses

• Smallest known type of infectious agent

• One of the worst enemies (HIV)

• Unique Structure• Invades all forms of

life

Rickettsias

• Way of Multiplying

• Its Location

• Transmission

• Examples– Typhus and Rocky-Mountain spotted fever

Protozoans

• Single-celled organisms

• 30 different types • Its Location

Fungi• Simple organisms

• Saprophytes

• Prefers dark and damp environments

• Invasion sites – Ex: ringworms or athlete's foot.

Transmission

Spread of infectious pathogens

People

• Direct contact– Ex. Hand shake, pregnant women to unborn

child

• Indirect contact– Ex. Cough, sneeze

Animals

• Dogs– Rabies

• Mosquitoes– Malaria and dengue fever

Contaminated Objects

• Examples– Eating utensils– Glasses – Toothbrush– Door knobs– Pencils– Computer mouse

Environment

• Careless disposal of waste

• Careless handling of foods

• Pollution in air and water

What’s wrong with this picture?

Immune Response

Nonspecific

vs.

Specific Resistance

Nonspecific Resistance

• Physical barriers– Mucus membranes and skin

• Chemical barriers– Tears, saliva, and acidic digestive juices

• Body cells– Phagocytes

Specific Resistance

• Lymphocytes– T-cells– B-cells

• Antibodies– Macrophages

Mission: Search and Destroy

Prevention

Immunity and Immunization

Immunity

• Active Immunity– The defense system the body develops to

protect one from diseases

• Passive Immunity– The temporary defense that an infant

acquires from its mothers

Immunization

• Passive Immunization– Immediate, short lived protection

• Active Immunization– vaccination

Test Your Knowledge

1. Mother to baby– Passive immunity

2. Flu vaccine– Active immunization

3. Acute poisoning treatment– Passive immunization

4. Hepatitis A vaccine– Active immunization

Test Your Knowledge Cont.

5. Tetanus vaccine– Active immunization

6. Chicken pox– Active immunity

7. Measles, mumps, and rubella vaccine– Active immunization

Common Sense Measures• Hand washing

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After using thebathroom

Beforehandling/eating food

Aftering changingdiaper

After petting cat/dog Aftercoughing/sneezing

After handlingmoney

Common Sense Measures

• Good Nutrition

• Regular exercise

• Bathe or shower daily

• Cover mouth when coughing or sneezing

• Avoid contact with people who are sick

• Avoid sharing of utensils

Come out, Come out Wherever you are?

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