Basics and Barriers
What is the main function of the immune system?
To protect the body from pathogens and foreign substances.
How does innate immunity differ from adaptive immunity?
Inborn, non-specific, quick immune response.
Which cells produce antibodies?
Plasma B cells.
MHC Class I presents to which T cell type?
What happens in an autoimmune disorder?
The body attacks its own cells.
What are the two main branches of the immune system?
Innate and adaptive.
What do Natural Killer (NK) cells do?
Surveille for abnormal cells (cancerous or virus-infected cells) and kill them before they can multiply.
What is the difference between active and passive immunity?
Active -- your body makes the antibodies
Passive -- you receive someone else's antibodies
MHC Class II presents to which T cell type?
Helper (CD4) T cells
What is an example of an autoimmune disease?
Lupus, rheumatoid arthritis, Type I DM
Give one example of a first-line defense.
Skin, mucus, stomach-acid, microbiome
What are the cardinal signs of inflammation?
Swelling, redness, heat, pain, possible loss of function.
What do cytotoxic T cells do?
Directly kill virus-infected or cancerous cells or release chemicals that kill them.
Which antibody is the most abundant and can cross the placenta?
IgG
What is alloimmunity?
An immune response to antigens from a different individual of the same species. Examples are pregnancy and rejection syndrome (transplant rejection).
What is an antigen?
A foreign substance that triggers an immune response.
What do interferons do?
Secrete chemicals that warn nearby cells of viral infections.
What is the function of helper T cells?
Release cytokines to activate B cells and other immune cells.
Which antibody is associated with MALT?
IgA
What is an allergy?
An overreaction to a harmless antigen.
How do vaccines help the immune system?
They create memory cells without causing illness, simulating a primary immune response.
What is the complement system?
A cascade of proteins that produce many reactions, including marking pathogens for death (opsonization), cell lysis, creating membrane attack complexes (MACs), and attracting other immune cells.
What are memory cells?
Cells that "remember" an antigen for future faster responses if they come into contact with the antigen again.
Which antibody is responsible for hypersensitive reactions (allergies)?
IgE
How does HIV affect the immune system?
The virus infiltrates and destroys helper T cells, which makes infected persons more susceptible to other infections.