Communicable Diseases Chapter 8

What are communicable diseases? Pathogens - living organisms or particles that can cause disease Communicable disease - a disease caused by pathogens that can be spread from person to person Can you think of any communicable diseases?

Types of pathogens Viruses – Microscopic particles that can reproduce inside living cells Examples: the common cold, the flu, Hepatits A, B, and C Bacteria – one-celled organisms that live almost everywhere on Earth Most bacteria are harmless but some can cause diseases such as: strep throat, gonorrhea, tuberculosis, Lyme disease, and anthrax

Types of pathogens Cont’d Fungi – living organisms that have some characteristics of plant cells but cannot make their own food Causes diseases such as: athlete’s foot and ring worm Protozoa – one-celled organisms that are larger and more complex than bacteria Examples: malaria and toxoplasmosis

How pathogens enter the body Direct Contact – touching, kissing, or other close contact with a person who carries a pathogen Indirect contact – contact with objects used by a person who has a pathogen Using a needle that has infected blood on it Inhaling air, eating food, or drinking liquid that carries pathogens Being bitten by an animal or insect that carries pathogens

BRAINSTORM Think about your typical day spent here at GVMS. Brainstorm and list TEN things you might touch during the day that you could infect if you were sick. 6. 2. 7. 3. 8. 4. 9. 5. 10.

Your body’s defense Immune system – organs, tissues and cells that destroy pathogens

First line of defense Mucus traps pathogens from entering the body Cilia – tiny hairs inside air passages that trap some pathogens that exit the body when you exhale or sneeze

Second line of defense Stomach acid Fever White blood cells Antibodies – protein substances in blood that can find, weaken or destroy certain pathogens

Third line of defense Immunity – resistance to a particular disease Vaccine – dead or weakened pathogens given for immunity Common childhood vaccines: Polio Pertussis Measles Chicken Pox Diptheria Tetanus

Avoiding communicable diseases Wash your hands before and after preparing food and after using the bathroom Cover your mouth when you sneeze or cough with a tissue or your sleeve Don’t share personal items