The Immune System Three Lines of Defense

Immune System Fight off disease and infection throughout the body

Transmission of Disease Direct Contact – (Contagious Disease) spread from one person to another by touching an infected person Examples – colds, STDs Indirect Contact – requires a carrier or vector Sneeze, infected surfaces Ingestion – contaminated water or food Amoebic dysentery and food poisoning (Salmonella), Botulism (canned food) – makes toxin and attacks nervous and respiratory system Bite – vectors Bubonic plague – spread fleas ,Malaria – mosquitoes, Lime’s disease– ticks, Rabies – dogs or squirrels

3 Lines of Defense First and second lines – fights most kinds of pathogens Third line of defense – protects against specific pathogens

1st Line of Defense Skin is your MOST important NONSPECIFIC defense->tries to block ALL pathogens

1st Line of Defense (NONSPECIFIC) JOB – to keep ALL pathogens out of the body Skin- unbroken skin acts like a _______ that blocks out most pathogens Mucus – lines mouth and nose – coats opening so pathogens can be eliminated or destroyed Tears-flush out pathogens Sweat – the salt and acid in sweat helps prevent the growth of harmful bacteria Stomach Acid – kills harmful pathogens that have entered the body BARRIER

Name your bodies 1st line of nonspecific defense and create your own analogy to explain how it works. b. What other nonspecific defenses does your body have? P.958

Amoebic dysentery Caused by parasite that eat the Intestinal wall of its host Caused: Contaminated food and Water Symptoms: Severe headache, abdominal pain, high temperature

2nd Line of Defense Inflammatory Response –reaction to tissue damage by injury of infection Damaged tissues release histamines,= _______ flow to the area. Histamines cause capillaries to leak, releasing phagocytes and clotting factors into the wound. __________ engulf bacteria, dead cells, and cellular debris Platelets move out of the capillary to seal the wounded area. blood Phagocytes

http://www.youtube.com/watch?v=K3JS_eekIs8

Differences What are 2 MAIN differences between the 1st and 2nd line of defense. What INITIALLY causes the Inflammatory (2nd line of defense) response? What chemical is released to start the inflammatory response? What type of immune cell comes to an open wound in skin to engulf any pathogens that do get in?

Third Line of Defense – Acquired Immunity Is the body’s resistance to previously encountered pathogens Primary Immune response – begins when the immune system encounters an new pathogen takes five to ten days for the body to reach its maximum production of B and T cells – Kill harmful pathogens

2. Secondary Immune Response -2nd time body is infected with the same pathogen – immune response is faster 3. Memory cells (both b and t cells) store information about the antigens they have encountered in the past

Immune Response If pathogens make it past the first two defenses the immune response occurs. Involves 3 major types of cells: Nail Infection

https://www.youtube.com/watch?v=zQGOcOUBi6s

brain cell Muscle cell stomach cell skin cell Antigen pathogen

pathogen

macrophage pathogen

antibody macrophage pathogen B cell

Once antibodies stop pathogen reproduction, macrophages/T cells kill them Killer T cell

Now you have immunity

15. Compare and contrast nonspecific and specific defenses. 16. Describe, in detail, the relationship between an antigen and antibody. 17. Explain why you only get chickenpox once (most people) but can get the flu almost every year.

1. Antibodies Protein that helps destroy pathogens Bind and link viruses and bacteria together Phagocytes then “eat” the pathogens <Antigen-Any substance that triggers immune response: virus, bacteria> Antibodies

2. Phagocytes AKA White Blood Cells Engulf pathogens and break them down “Eat & Destroy” Phagocyte

3. Lymphocytes AKA T-Cells 2 Types: Helper T-Cells activate Killer/Cytotoxic T-Cells Killer/Cytotoxic T-Cells destroy pathogens Killer T-cell attacks and destroys a pathogen

18. Describe the roles of each type of immune cell 18. Describe the roles of each type of immune cell. (antibodies, Phagocytes/macrophage, Killer(cytoxic T cells) 19. Explain what is in a vaccine and how vaccines lead to immunity.

How HIV is Transmitted ANY sexual intercourse (even protected is risky) Sharing needles Contact with infected blood (From infected mother to child During pregnancy, or breast feeding)

http://www.youtube.com/watch?v=7mZ8Yu5pT6I http://www.youtube.com/watch?v=odRyv7V8LAE

HIV/AIDS Retrovirus, contains RNA Spread only by blood and bodily fluids Virus invades/attacks helper T-Cells Uses T-Cells to make more HIV T-Cells are destroyed Loss of T-Cells= LOSS OF IMMUNITY Mutates frequently No vaccine or cure Mature Human Immunodeficiency Virus (HIV)

What is the relationship between HIV and AIDS? What are 2 ways HIV CAN be spread and 2 ways it can NOT be spread?

Can you acquire HIV toilet seats? Yeah, if you do some pretty unusual things with toilet seats that have been contaminated with risk body fluids (blood, semen, vaginal secretions) form an infected person, there would be some risk of infection but it would not be great. What are the chances of a person with an open sore on their buttocks sitting on a toilet seat covered with one or more of the risk fluids??