Flashcards in SC8 #5 Immune system Deck (22):
What does the immune system do?
Fights and guards against pathogens, which are found everywhere and can infect people with a range of diseases
How can diseases be passed on tho other people?
Direct contact, indirect contact, infected food/drink and animal bites
What does the first line of defense do?
1. skin stops pathogens from entering
2. sweat and oil kill pathogens
3. gastric juice destroys pathogens
4. mucus in nose keeps pathogens out
What does the second line of defense do?
If a pathogen makes it past the first line of defense, the body mounts an immune response to destroy it.
Success depends on body's ability.
What are the two types of immune response?
Innate and acquired
What is innate immune response?
All living things are born with it.
Fluid flows to the site of the infection (aka inflammation).
Increase in white blood cell phagocytes
What do phagocytes do?
Chemically digest pathogens
What is acquired immune response?
A very specific attack on an antigen.
May take up to a week to develop.
What is an antigen?
A non-living particle or substance, carried by phagocytes
What do B cells do?
Recognize antigens and produce antibodies to fight them
What are Memory B cells?
Specialized B cells that are stored in the body and get reactivated when the pathogens reappear
What do Helper T cells do?
Recognize antigens and activate B cells
What do Killer T cells do?
Directly destroy antigens or pathogens
What are vaccines and give a few examples
A weakened or dead form of a pathogen.
Ex: flu, tetanus, diphtheria, pertussis etc
What are allergies?
Hypersensitivity to allergens of the immune system
What is AIDS?
Caused by HIV and shuts down immune system
What is a pathogen?
A living thing that causes disease
What is the role of antibodies?
1. Bind to antigens to make them harmless
2. Mark antigens for later destruction
3. Protect the body from future infections
What do allergens do?
Causes allergic reactions
What is histamine?
A chemical that the body releases when it fights invaders
How does a vaccine work?
Stimulates your immune system to produce more antibodies