Nonspecific Defense
http://montieandme.files.wordpress.com/2009/07/germs.jpg
http://fatfeministfitnessblog.blogspot.com/2009/09/food-poisoning.html
http://www.brainpop.com/health/bodysystems/immunesystem/
The human body's first line of defense is the nonspecific defense, also called innate immunity. It does not distinguish microbes from each other. There are two lines of defense:
The first line is a barrier that prevents pathogens from entering the body.
Mechanical barriers-Skin has glands that secrete acids that inhibit the growth of many microbes.The hair in your nose filters incoming air. Cilia on cells lining the tubes sweep mucus upward and out of the system.
Chemical barriers-Body fluids such as sweat, saliva and tears digest the cell walls of many bacteria. mucous membranes release mucus to trap microbes. Stomach acids also kill most bacteria swallowed with food or saliva.
Fever- helps defend against bacteria that cannot function at the high temperature
The second line of defense encounters microbes that make it past the first line. Their goal is to limit the spread of invaders. The inflammatory response is to increase the blood supply to the area, bringing nutrients such as oxygen and white blood cells to fight disease. Phagocytes engulf microbes in infected tissues. The three types of phagocytes are granulocytes- first stand during an infection, attack any invaders and eat until they die, macrophages- larger, live longer, also alert the rest of the immune system. They start out as white blood cells but eventually leave the blood stream. Dendritic cells- devour intruders and also help activate the rest of the immune system. They can filter body fluids to clear them of foreign organisms. Interferons are chemicals released by the immune system to block against viral infections.
The first line is a barrier that prevents pathogens from entering the body.
Mechanical barriers-Skin has glands that secrete acids that inhibit the growth of many microbes.The hair in your nose filters incoming air. Cilia on cells lining the tubes sweep mucus upward and out of the system.
Chemical barriers-Body fluids such as sweat, saliva and tears digest the cell walls of many bacteria. mucous membranes release mucus to trap microbes. Stomach acids also kill most bacteria swallowed with food or saliva.
Fever- helps defend against bacteria that cannot function at the high temperature
The second line of defense encounters microbes that make it past the first line. Their goal is to limit the spread of invaders. The inflammatory response is to increase the blood supply to the area, bringing nutrients such as oxygen and white blood cells to fight disease. Phagocytes engulf microbes in infected tissues. The three types of phagocytes are granulocytes- first stand during an infection, attack any invaders and eat until they die, macrophages- larger, live longer, also alert the rest of the immune system. They start out as white blood cells but eventually leave the blood stream. Dendritic cells- devour intruders and also help activate the rest of the immune system. They can filter body fluids to clear them of foreign organisms. Interferons are chemicals released by the immune system to block against viral infections.
http://www.humanillnesses.com/images/hdc_0001_0001_0_img0010.jpg
Background:Blood stream with white blood cells
http://www.aaaai.org/Aaaai/media/MediaLibrary/Images/Conditions/Library/93848554-blood-cells-cropped.jpg
http://www.aaaai.org/Aaaai/media/MediaLibrary/Images/Conditions/Library/93848554-blood-cells-cropped.jpg