Pathogens Cause Disease

Being Sick Can Really Get Ya!

Add these terms and definitions to your notes sheet

• Immunity- the resistance to a sickness.

• Infection- When a pathogen invades, multiplies, and causes harm.

Disease

Internal Causes• Genetic diseases

– Down’s syndrome– Albinism– Hemophilia– Sickle cell anemia

External Causes• Infections by other

organisms• Environmental factors

Toxic pollutants - Ex: Smog, industrial smoke, cigarette smoke, harmful vapors, vehicle emissions, pesticides

MICROORGANISMS- ARE SMALL ORGANISMS THAT CAN ONLY BE SEEN WITH A MICROSCOPE (VIRUSES ARE NOT MICROORGANISMS!)

Parasites

Tapeworm

Any agent (any living or nonliving thing) that causes disease.

Viruses

Viruses

• **They are NON LIVING**–Need a host to reproduce–Can not respond to changes in their

environment–Does not grow

• Contain genetic material• Come in many sizes and shapes• Very small, about 1/10,000 bacteria cells

Viruses Multiply Inside Living Cells

• Attachment-They attach to a host cell

• Injection- Injects DNA into a cell

• Production- Host cell makes copies of virus DNA

• Assembly- New viruses assemble in cell

• Release- Cell bursts releasing viruses

Harmful Viruses Cause Huge Problems

• Diseases caused by Viruses– Colds– AIDS– Polio– Small Pox– Diphtheria– Influenza

• Can affect Plants, Animals, and Bacteria

Viruses and Vaccines

• There are no cures for viruses, doctors use vaccines to prevent people from getting sick from harmful viruses.

• Vaccine- contain small amounts of weakened or dead pathogens that stimulate an immune response.

• You can be vaccinated at any age and you need to stay up to date on your vaccinations in order to stay protected.

Vaccines

Prevention

Viruses

Bacteria

Bacteria

• **They are LIVING**• Prokaryotic (no nucleus)• Unicellular• Both autotrophic & heterotrophic• Disease causing bacteria are heterotrophic.

Bacteria• Most are helpful (99%) few are harmful (1%)• Can be spread through food, water and air• Come in three different shapes– Spiral shaped– Rod shaped– Round shaped

Bacteria Prevention and Cures

• Can be prevented with vaccines and treated with antibiotics.

• You can prevent the spread of bacteria

Bacteria

Bacteria Vs. Viruses

Bacteria

• Living• Vaccines & antibiotics• Harmful and helpful• Bigger than a virus• Has a cell wall

Viruses

• Non-living• Vaccines • Needs a host cell• Harmful and helpful• Smaller then a bacteria

Virus vs. Bacteria

Fungi

Fungi

• Eukaryotic (has a nucleus)• Heterotrophic• Unicellular and multicellular• Can be helpful and harmful• Can be used to make antibiotics• Many produce harmful chemicals• Can cause disease in humans

Fungal infections

Ringworm

•Ringworm•Athlete’s foot•Under nail fungal infections•Thrush (in babies)

Treatments•Creams and ointments•Antifungal medications

Parasites

How Parasites Are Spread

• Insect bites• Animal feces• Walking barefoot• Handling raw meat and fish (not washing after)• Eating raw or undercooked pork, beef or fish• Eating contaminated raw fruits and vegetables• Eating meals prepared by a contaminated person• Drinking contaminated water

Examples

• Tapeworm• Hookworm• Lice• Malaria• Pinworm

Insect bites & Malaria

Prevention

• Cook food entirely• Wash hands after handling raw meats• Wash fruits and vegetables• Don’t eat sand from sandboxes • Make sure water is safe to drink or boil it• Wash hands after cleaning kitty litter box

Cancer• *When your own cells multiply uncontrollably, destroying

healthy tissue* • Disorder that affects the cell cycle• Not a single disorder, rather a group of disorders• It is the uncontrolled division of cells• Can spread to various tissues, the cells are selfish• Cancer cells become “immortal” they continue to divide• Most are caused by cell mutations during a persons lifetime• Many are caused by harmful chemicals “carcinogens” (ex.

nicotine, UV rays, radiation, x-rays)• Some inherit a tendency for a particular cancer

Cancer Prevention

• You can reduce the risk of getting a cancerous (malignant) tumor by:– Eating a healthy diet– Exercising regularly– Limiting alcohol– Maintaining a healthy weight– Minimizing your exposure to radiation and toxic chemicals– Not smoking or chewing tobacco– Reducing sun exposure, especially if you burn easily– Get screenings when possible

Cancer