Chapter 16 Flashcards
what is adaptive immunity
the body’s ability to
recognize and defend itself against distinct
invaders and their products
5 attributes of adaptive immunity
Specificity • Inducibility • Clonality • Unresponsiveness to self • Memory
2 types of adaptive immune responses
cell-mediated immune responses and antibody immune responses (humoral immunity)
primary and secondary lymphoid organs
primary- red bone marrow and thymus
secondary- lymph nodes, spleen, tonsils, and mucosa-associated lymphoid tissure (MALT)
properties of antigens
Molecules the body recognizes as foreign and
worthy of attack
• Recognized by three-dimensional regions called
antigenic determinants/epitopes on antigens
• Large foreign macromolecules make the best
antigens
• Include various bacterial components as well as
proteins of viruses, fungi, and protozoa
types of antigens (3)
exogenous, endogenous, and autoantigens
define exogenous antigens
Exogenous antigens— include toxins and other components of microbial cell walls, membranes, flagella, and pili
define endogenous antigens
—produced by
microbes that reproduce
inside a body’s cells
define autoantigens
derived
from normal cellular
processes
Roles of the Major Histocompatibility Complex
(MHC) and Antigen-Presenting Cells
• Group of antigens first identified in graft patients
• Important in determining compatibility of tissues for tissue
grafting
• Major histocompatibility antigens are glycoproteins found
in the membranes of most cells of vertebrate animals
• Also know as human leukocyte antigen (HLA) system
• Hold and position antigenic epitopes for presentation
to immune cells
2 classes of MHC proteins
MHC class I- present on all cells except RBCs MHC class II- Present on antigen-presenting cells (APCs) • APCs include-macrophages and dendritic cells
describe T lymphocytes
Produced in the red bone marrow and mature in the thymus • Circulate in the lymph and blood • Migrate to the lymph nodes, spleen, and Peyer’s patches • Have T cell receptors (TCRs) on their cytoplasmic membrane
3 types of T lymphocytes
cytotoxic t cells, helper t cells, and regulatory t cells
cytotoxic cells ____
directly kill other cells
helper T cells regulate ______
B cells and cytotoxic t cells
what do regulatory t cells do
represses adaptive immune responses
four fates that immature t cells undergo
T cells that do not recognize body’s MHC protein undergo
apoptosis
• T cells that recognize autoantigen die by apoptosis
• Some “self-recognizing” T cells become regulatory
T cells
• T cells that recognize MHC protein and foreign epitopes
become repertoire of protective T cells
b cells are found primarily in the ______
spleen, lymph nodes and MALT
major function of B cells
secretion of antibodies
each b lymphocyte has multiple copies of the ____
B cell receptor (BCR)
antibodies are ______similar to BCRs
immunoglobulins
what region of the antibody contains the antigen-binding sites
the arms or the Fab region( fragment antigen binding)
the antibody stem is called
Fc region (fragment, crystallizable)
5 basic types of stems and these form the 5 classes of antibodies which are
IgM, IgG, IgA, IgE, and IgD
