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

**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

**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

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 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