Final Exam Ch 18 Flashcards
(40 cards)
antigens
substances that cause the production of antibodies
* usually components of invading microbes or foreign substances
antibodies
interacting with epitopes, or antigenic determinants
innate immunity
body’s immediate defense against any pathogen
adaptive immunity
slower-acting response that develops memory, defenses that target a specific pathogen
Adaptive immunity is defined by two characteristics, what are they?
- primary response: first time the immune system combat a particular foreign substance
- secondary response: later interactions with the same foreign substance; faster, and more effective due to “memory”
Action of T Lymphocytes
- used for cellular immunity
- cell mediated immunity
- originate in the red bone marrow
- matures in thymus gland
- can be divided into three classes
- secret cytokines instead of antibodies
Three classes of T Lymphocytes
- Helper T cells (CD4) - recognize antigens presented on the MHC II
- Cytotoxic T cells (CD8) - recognize antigens present on the MHC I, secrets granules and perforins
- Regulatory T cells
helper T cells (CD4)
recognize antigens presented on the MHC II
cytotoxic T cells (CD8)
recognize antigens present on the MHC I, secrets granules and perforins
Action of B lymphocytes
- used for humoral immunity
- originates in red bone marrow
- matures in bone marrow
- final stages in spleen
- differentiate into Plasma B Cells and Memory B Cells when they recognize antigens/pathogens presented by APCs (antigen presenting cells)
Plasma B cells: produce antibodies
Memory B Cells: retain memory of the specific pathogen/antigen
Major histocompatibility complex I (MHC):
- MHC class I are on the membrane of nucleated animal cells
- Identify “self”
MHC class Il (Major Histocompatibility Complex):
are on the surface of antigen-presenting cells (APCs), such as macrophages, dendritic cells and B cells
** Identify abnormal or nonself pathogen antigens for the initial activation of T cells
steps of humoral immunity
B cells or B lymphocytes
* Originates in the red bone marrow
* Matures in the bone marrow
* Final stages in the spleen
* B cells differentiate into Plasma B cells & Memory B cells when they recognize antigens/pathogens presented by
APCs(antigen presenting cells)
* Plasma B cells produce antibodies
* Memory B cells retain the memory of the specific pathogen/antigen
steps of cell mediated immunity
T cells or T lymphocytes
* Originates in the red bone marrow
* Matures in the Thymus glands
* T cells can be divided into three classes-helper T cells (CD4 cells), cytotoxic T cells (CD8 cells) and regulatory T cells
* T cells act with the T cell receptors which secrete cytokines when they recognize antigens/pathogens presented by the APCs
* CD4 helper T cells recognize antigens presented on MHC II
* CD8 cytotoxic T cells recognize antigens presented on MHC I
epitopes
smaller exposed regions on the surface of antigens
* importance so that antibodies and T cells do not recognize and interact with an entire antigen, but with a smaller exposed regions on the surface of antigens
5 classes of immunoglobulins
- IgG
- IgM
- IgA
- IgD
- IGE
IgG
- typical Y shape aka monomer
- most abundant in serum (accounts for 80% of serum antibodies)
- in the blood, lymph, and intestine
- maternal IgG antibodies cross placenta which protect the fetus
IgE
- Y shape aka monomer
- less than 1% of serum antibodies
- Fc binds to mast cells and basophils
- In blood
- concentration increase during allergic reactions or parasitic infections
- cause the release of histamines when bound to antigen: lysis of parasitic worms
IgD
- Y shape aka monomer
- Less than 1% of serum antibodies
- in the blood, lymph, and on B cells
- no we’ll defined function: assists in the immune response on B cells
IgA
- Monomer in serum; DIMER in secretions
- 13% of serum antibodies
- produces salivary amylase and other body secretions
- Common in mucous membranes and body secretions (mucus, saliva, tears) and breast milk
- Prevent microbial attachment to mucous membranes
- can survive the gastrointestinal tract environment
IgM
- primary response antibody
- PENTAMER (five monomers held with a J chain)
- 6% of serum antibodies
- In the blood, in lymph, and on B cells
- Cause clumping of cells and viruses
- First response to an infection; short-lived
components of adaptive immunity
- humoral (antibody-mediated)
- cellular (cell-mediated) component
humoral immunity
- produces antibodies that combat foreign molecules known as antigens
- recognize antigens and make antibodies
- B cells are lymphocytes that are created and mature in red bone marrow; these make the antibodies in humoral immunity
cellular immunity
- Produces T lymphocytes
- recognize antigenic peptides processes by phagocytes cells
- T cell receptors (TCRs) on the T cell surface contact antigens, causing the T cells to secrete CYTOKINES instead of antibodies
- responsible for destruction of cells infected with intracellular pathogens
