1.5: THE IMMUNE SYSTEM

BRAINSTORM! What do you already know about the immune system? What organs and body parts are involved?

Immune system = the system that defends the body against infection and disease - causing substances such as bacteria, viruses and cancer cells. contains several lines of defence that help protect us from pathogens (microorganism that can cause disease)  

Watch the following video linking the immune system to the cell https://www.youtube.com/watch?v=oqGuJhOeMek

The first line of defence includes: the skin and the lining of internal body systems. sweat and natural body acids that kill some pathogens on the surface of your skin

Hairs (cilia) in the respiratory system to trap and sweep pathogens away. Phlegm and mucus trap pathogens

strong acid in your stomach kills many types of Pathogens   strong acid in your stomach kills many types of Pathogens

How might our immune system be different without this first line of defence?

The second line of defence includes: White blood cells which engulf and kill pathogens, realease chemicals that aid in this process

Inflammation = the body’s response to injury or infection Inflammation = the body’s response to injury or infection. The affected area received extra blood to allow more white blood cells to arrive. Temperature increases for an antibiotic effect causes the affected area to become red and swollen

Why does inflammation occur after an injury or infection Why does inflammation occur after an injury or infection? How does this help your immune system fight disease?

The third line of defence includes: specialized white blood cells that remember what a pathogen looks like so that the immune system is ready for future attacks. Watch The Magic School Bus: Inside Ralphie, and fill out the accomanying worksheet!

ACTIVITY: THE SPREAD OF DISEASE!! Take ONE beaker Each cup contains some liquid with one cup containing a fake “pathogen” Walk around the class and “shake hands” with 3 people pour your beaker into the other persons and then pour half the liquid back into your beaker. Do this with 3 different people Record who you interact with: What does the dropper of liquid represent? If your cup turns pink after the “infection indicator” is added then you have been infected, if it does not then you are safe Your name Contact 1 Contact 2 Contact 3 Contact 4

Explain how this activity demonstrates how an infectious disease is transmitted?

Outbreak Epidemic Pandemic A sudden occurrence of disease in a community where the number of affected individuals is greater than expected Epidemic A disease that spreads to many people rapidly in an area Pandemic An epidemic that has spread over several countries or continents, or around the world

Outbreak Epidemic Pandemic Example: E Coli food poisoning Example: Ebola (Most cases were in West Africa) Pandemic Example: Spanish Fever and Bubonic plague HIV and AIDS