Microbiology Lecture - Chapter 17 Adaptive Immunity-Specific Defenses of the host Flashcards
Characteristics of adaptive immunity
slower than innate
response depends on specific foreign entity
acquired (based on exposure)
Two components humoral and cellular
Third line of defense is?
T cells and B cells
Why is the adaptive immune system slower than the innate?
because it has to process what the foreign substance is that it is coming across in order to produce antibodies
produces antibodies in the whole body to fight off same microbe in the future
The humoral component has to do with__________.
The cellular component is __________.
Source of lymphocytes
Stem cells- before birth/liver
after birth/bone marrow
Stem cell differentiation- bone marrow (B cells)
thymus (T cells)
Stem cell migration- B and T cells migrate to lymphoid tissues and blood
Not all can induce the immune system response
substances that cause the production of antibodies
typically a protein or polysaacharide (sugar)
molecular fragments on surface of foreign entities
produced by B cells (plasma cells)
recognize and bind to a specific antigen
-bind to a particular region on a molecular fragment (epitope)
Bacterial antigens can be found on:
Antigens may have several epitopes. Epitopes are a region on an _______ and a binding site for ______.
an antibody binding to an epitope can turn the complementary system on
Haptens are ________________.
Are epitopes that are too small to induce an immune response it needs a carrier molecule
antigen of low molecular weight
Antibodies are also called
Antibodies are ______________.
globular soluble protein molecules
are present in body fluids such as milk, serum and gastric secretions
There are 5 major classes of antibodies they are
G- IgG Most common circlating
Structure of an antibody:
4 chains- 2 heavy and 2 light
the disulfide bridge holds the 2 pieces together
the body is the stem
the variable light and variable heavy bind to the epitope
B cells function
antibodies and memory cells
What is MHC?
major histo compatibility complex
True or false B cells have antibodies on the surface?
B cells become activated when________ bind to ______ .
Antigen fragments bind to MHC. The MHC displays the fragments to __________ .
The MHC goes outside the B cell and tells the immune system
this piece I am holding out is foreign but do not destroy the B cell that is self
B cells sometimes require help from?
T cells known as 'helper' T cells
The T helper cell binds to the MHC antigen complex which does the following:
activates the T cell----> cytokine (chemical signal) ----> further activates B cell -----> make memory cells and mass produce antibodies
Plasma cells are
antibodies are then released into the blood stream
Memory cells are
secondary response to an antigen
What are other antigen producing cells?
reduces the number of infectious units to be dealt with
highlighter flags antigen for the immune system-coating antigen w antibody
the microbe is covered and can't adhere to the cell wall
activation of complement system
causes inflammation and cell lysis
Antibody dependent cell mediated cytotoxicity
lysis the cell from outside- helminths, parasites