Where do lymphocytes mature?
in the bone marrow or lymph system, where the precursors will differenitate into T or B cells
The success of the immune system hinges on..
the cooperation and function of both cell-mediated and antibody-mediated immunities
Activated B lymphocytes are..
plasma cells. either directly or indirectly when stimulated B Lymph develop into plasma cells
What do T lymphocytes do?
recognize specific antigens, can directly attack abnormal cells, called cell-mediated immunity
What 2 precursor cellw will the functional lymphocytes differentiate into?
T cells in the thymus
B cells in the bone marrow
Where do they circulate to have the highest chance of comming in contact with an antigenic match?
Success of the immune system hinges on what?
the cooperation and function of both cell-mediated and antibody (humoral) immunities
Activated B lymphocytes are what
plasma cells, when stimulated they either directly or indirectly become these
What are the proteins released from plasma cells called?
antibodies this is called antibody-mediated immunity
What do T lymphocytes do?
recognize specific antigens, can directly attack abnormal cells, and cell-mediated immunity T helper, T cytoxic, T memory, T regulator=T suppressor
What is an antibody?
a protein molecule that can bind strongly to an antigen, binding is so strong it is almost covalent
What is an antigen?
is a molecule recognized by products of the immune system T and B lymphocytes and antibodies
What does an antigen do?
identifies the cell as SELF or NON SELF, identifies the type of cell, can elicit and immune response
An antigen is more immunogenic if it is..
lare, organic, complex in structure, foreign "non-self" or at least recognized as non-self
What happens if an antigen is large and complex?
there can be multiple immunogenic portions of the antigen this is called antigenic determinants or epitopes
Can medications act as haptens and why?
yes because if they bind to something like a RBC surface protein and it could then become immunogenic
What cells are involved in adaptive immune system?
T cells cell-mediated B cells antibody-mediated and both B and T cells produce memory cells to speed responses
What is active immunity
the body respons to a pathogen (antigen) to make antibodies LONG TERM IMMUNITY
What is passive immunity?
the body simply receives antibodies with no effort of its own. SHORT TERM IMMUNITY
Examples of natural passive
a baby receives antibodies from its mother through the placenta and breast milk
Examples of artificial active
a person receives an injection of an attenuated pathogen that stimulates the body to form an antibody
Cell-mediated immunity involved which cell types?
T helper=CD4 T cytoxic=CD8 T regulator=T suppressor
What are Natrual Killer (NK) cells?
non-T or non-T lymphocytes, they squeeze out of boodstream and into tissues, cells that lack MHC 1 molecules, trigger an apoptotic signal in their victim
T helper CD4 cells do what?
are recruited by advertising of antigens displayed by MHC 11 markers on the surface of APC
What do CD4 cells do when found?
they release IL-2 and stimulate cell division by autocrine activation
After CD4 release IL-2 what happens?
divide to form T memory cells-speed future responses; T helper1 cells-cell mediated immunity; T helper2 cells- antibody-mediated immunity
T cytotoxic CD8 cells do what?
activated by T helper, when activated release compounds that kill cancerous or virally infected cells, apoptosis is preferred for virally infected cells and perforin used to trigger cytolysis
Cytotoxic T cells do what?
they destroy infected cells that display viral antigens on their membranes
What to T regulator/suppressor cells do?
seem to supress immune responses and save normal cells from destruction.
How are virally infected cells killed?
antigen-presenting cells such as macrophages, helper T cells, and cytotoxic T cells all participate in destroying virally infected cells
What are the 2 ways T cells die?
virus infected or cancerous cells may be killed if a T cell receptor matches antigen displayed by MHC 1 molecules on their cell surface. some viruses and cancer cells evade detection by hiding MHC 1 cell surface receptors these cells are killed by NK cells
What are immunoglobulins (antibodies)?
are distinguished by a number of characteristics, distinguished by structure, location, and function IgM IgG IgA IgE IgD
What are IgM's?
immunoglobulin, petamer, 10 heavy and 10 light chains, very effective activator of the complement system
What are IgG's?
monomer, actively transported accross the placenta, longest half-life of the immunoglobulines, LONG term immunity
What are IgA's?
located in the plasma and body secretions, sIgA contains a secretory component (protects from enzymatic destruction- lacrimal glands, salivary glands, and lymph in breasts, bronchi GI tract
What do IgA protect against?
pathogens that are inhaled, swallowed, or come in contact with external surfaces.
What are IgE's?
low plasma concentration, bound to eosinophils, basophils, and mast cells, triggers release of histamine from mast cells