Immune system Flashcards
What are the two main functions of the immune system
1.To recognize invading pathogens-(disease-producing bacteria,
fungi,protozoa and viruses)as being distinct from normal body
components (and hence treated as foreign
2. To trigger pathways that will destroy the invading pathogens (activation of
complement and phagocytic cells that engulf and digest the
invading organism.
what are the two immune systems
- Humoral
- Cellular
What does humoral immune system rely on?
B lymphocytes to produce soluble antibodies that will bind the foreign antigens
What does the Cellular immune system rely on?
uses T lymphocytes that recognize and destroy invading cells directly
Why a B lymphocytes called b lymphocytes
because the cells mature in the bone marrow
Aka B cells
Why are T lymphocytes call t lymphocytes
because their maturation from stem cells occurs in thymus
Aka cytotoxic T lymphocytes
Aka T cells
what are the types on immune response
- primary
- secondary
primary immune response
occurs on initial contact with a foreign
antigen and results in production of immunoglobulin M(IgM) and then
immunoglobulin G(IgG).
Secondary immune response
occurs when same foreign antigen is encountered again and immunological memory leads to the response
the response produces a much more rapid and larger increase in specific IgG production
Antigens
identified foreign invaders or components
Clonal selection Theory
Explains operation of humoral immune system like:
❑A large number of antibody-producing cells exist in an animal even
before it encounters a foreign antigen ,each cell producing only one
specific antibody and displaying this on its cell surface.
❑An antigen binds to cells that display antibodies with appropriate
binding sites and causes proliferation(rapid increase) of those cells to form clones of
cells secreting the same antibody in high concentration
Self tolerance
The inability to make antibodies against self
in Autoimmune diseases ?
the immune system loses its tolerance against self antigens.
