1. Disease EQ: How are diseases transmitted?

2. Definition of a Disease The growth of a pathogen that begins injuring cells and tissues Spread from contact with an infected person or surface

3. Germ Theory Old school – disease was caused by an evil spirit or by doing evil deeds Early Work – Pasteur and Koch showed disease was actually caused by microorganisms Koch’s Postulates –The microorganism is always found in the ill person –The microorganism can be isolated from the ill person and grown in a growth medium outside the body –When the microorganism is then injected into a healthy person that person gets sick with the illness –The microorganism can be isolated from the newly sick person

4. Agents of Disease Viruses –Non-cellular particles that use the cell’s mechanisms to reproduce more viruses and then ruptures the cell to escape –Examples: chicken pox, the common cold Bacteria –Infect tissue directly growing in infected cells killing them –Produce toxins –Examples: lime disease, TB, flesh eating bacteria Fungi –Rapid growth in skin tissues causing irritation and infections –Examples: ringworm, athletes foot Protozoans –Small microorganisms –Live in body and irritate body systems –Examples: malaria, Montezuma's revenge

5. Non-Specific Defenses

6. First Line of Defense Not specific to any one pathogen Primary source of preventing disease from infecting the body

7. Skin –Acts as a barrier to prevent bacteria and viruses from entering the body –Very few pathogens can enter through the skin –Very effective if unbroken Bacteria and viruses will enter through the orifices like the nose, mouth, and eyes

9. Mucus / Cilia –All natural orifices are protected from disease entering the body by tiny hairs and snot like material –Mucus is the silvery excretion that traps particles –Cilia are hairs that filter out disease particles –Many of the secretions contain lysozyme which is an enzyme that breaks down the walls of bacteria

11. Phagocytes White blood cells that target and engulf the invading disease particles Not specific to any particular pathogen Produced in the lymph nodes of the body – this is why your lymph nodes swell when you are sick Creates swelling at the site of a wound This is the pus when you pop a pimple

13. Fever A rise in the bodies temperature –Stimulates the white blood cells –Can kill some pathogens as they are taken out of their ideal temperature range –Should not always be treated with a drug As long as it is low grade it is doing more good for your body than harm Only becomes harmful when it goes above 102

14. Interferon An enzyme produced by a virus infected cell that helps block viral reproduction Slows down the infection so that specific defenses can begin to work