Chapter 40-1 Notes
The Immune System
Agents of Disease:
Pathogens: Disease causing agents
Examples: bacteria, viruses, and fungi
Virus: Tiny Particles that invade and replicate within living cells.
§ viruses attach to the surface of the cell
§ insert their genetic material in the form of RNA or DNA into the host cell
§ Replicate within the host cell
§ Take over the functions of the host cell
Examples: HIV, Avian Flu, the Flu, Colds, Herpes, HPV, Chicken Pox, Small Pox, Measles, Mumps, West Nile, Malaria, Rabies, Hantavirus, Lyme disease
Bacteria: Single celled Prokaryotes. Most are harmless but some cause serious disease.
1. Break down the tissues of the infected organism for food
2. Release toxins that harm the body
Examples: Streptococcus, diphtheria, botulism, anthrax, gonorrhea, syphilis, Chlamydia
How Disease is Spread:
1. Some infectious diseases are spread from one person to another through coughing, sneezing, or physical contact.
§ The air acts to carry the thousands of droplets released.
§ Pathogens can settle on objects and you can get them by touching them.
§ It is important to wash your hands often with soap and water. Cover your mouth when sneezing or coughing.
2. Some pathogens are spread through contaminated water or food.
§ Partially or uncooked meat can spread disease.
§ Food sitting out too long.
§ Food prep people not washing their hands after using the bathroom.
§ Contaminated water caused by poor sanitation and untreated sewage.
3. Some pathogens are spread by infected animals.
§ Mosquitoes, ticks, wild animals and mice are often carriers of viruses
4. Some are spread through the exchange of bodily fluids.
§ HIV is caused by the exchange of blood or semen.
Fighting Infectious Disease
Antibiotics: Compounds that kill bacteria without harming the cells of the human or animal hosts.
§ Antibiotics work by interfering with the cellular processes of microorganisms.
§ Antibiotics do not work on viruses.
§ It is important not to take antibiotics unless you are really sick with a bacterial infection because this causes the bacteria to mutate and change into something we do not have an antibiotic for.
§ Viruses either have to run their course; drink water and rest.
§ Some viruses have vaccines made from dead viruses. Some viruses do not have vaccines and will cause death. Vaccines must be given BEFORE you get the virus.