Immune system Chp. 21 (Questions 13-21) Flashcards
What is the sequence of humoral immunity?
- B-cell stimulation
- B-cell activation
- clonal selection
- plasma cells
- antibodies
- attack!
- memory
What is B-cell stimulation?
antigen-lymphocyte interaction. assistance of helper T cells.
What is clonal selection?
mitosis of B cells
What is the role of plasma cells in humoral immunity?
be an antibody factory, become memory B cells.
What is the secondary response?
makes antibodies faster and in greater abundance. no noticeable symptoms.
What is the basic structure of an antibody?
Figure 21.14 Pg. 781
four polypeptides - two short light chains and two long heavy chains
What are the main classes of immunoglobins?
IgM, IgA, IgD, IgG, IgE
What are the four ways the antibodies eliminate the antigen?
- neutralization- masks dangerous parts of bad guy
- agglutination- binds to multiple pathogen, clumping
- precipitation- soluble antigens. clumping. in fluid.
- complement fixation- makes hole in cell. cell lysis.
What are the different types of T-lymphocytes and their functions?
- Cytotoxic T-cells (Tc): destruction of a pathogen.
- Helper T-cells (Th): promote the action of other t-cells
- Regulatory T-cells (Treg): limit the attack of cytotoxic T-cells
- Memory T-cells (Tm): recognize the pathogen for when exposed again
What is the sequence of cellular immunity?
- antigen presentation
- t-cell activation
- clonal selection
- attack
- Treg release chemicals that inhibit Tc
- t-cell recall response
What occurs during antigen presentation?
antigen presenting cells partially destroy pathogen, and displays epitope
What occurs during the attack response?
Tc attacks pathogen, its a direct attack. t-cell binds to infected cell & injects cytotoxic chemical (perforin) which makes holes in membrane.
What is the T-cell recall response?
Tm turns into Tc during re-exposure.
How do the Tc cells defeat the pathogen?
Tc cells bind to infected cells and inject cytoxic chemicals (perforin) which makes a hole in the membrane. then the pathogen is injected with gransymes which cause apoptosis, which is cell-suicide.
Identify the difference between active and passive humoral immunity.
active immunity creates a permanent resistance while passive is a temporary resistance.
what is the difference between natural and artificially obtained immunity and examples?
natural- naturally being infected with a virus. getting sick on your own.
artificially- purposely being given a dead pathogen via injections. vaccines.
What is hypersensitivity?
immune system reaction to an antigen that most tolerate just fine. example-an allergy
What is the difference between immediate and delayed hypersensitivity?
immediate hypersensitivity- symptoms occur right away
delayed hypersensitivity- takes 1-3 days before you see symptoms
Give examples of type I, II, III, and IV hypersensitivity reactions.
Type I: immediate sensitivity. causes mucus hypersecretion, local edema. in extreme cases anaphylactic shock.
Type II & III: subacute, slower onset, longer duration. IgG or IgM.
Type IV: delayed hypersensitivity. cell mediated response. Tc
What is autoimmune disease?
failure of self-tolerance. antibodies fail to distinguish self-antigens from foreign-antigens.
What are some examples of autoimmune diseases?
lupus, rheumatoid arthritis, multiple sclerosis, type 1 diabetes mellitus, graves disease, crohn’s disease, AIDS etc.
What is the virus that leads to Acquired Immunodeficiency Syndrome (AIDS)?
HIV: Human Immunodeficiency Virus
What does HIV destroy?
HIV invades helper t-cells, dendrites, and macrophages
How does HIV lead to a suppressed immune system?
HIV destroys helper t-cells which depresses cellular immunity
How is HIV transmitted?
blood, semen, vaginal secretion, and breast milk
What are the current treatment strategies for AIDS?
- prevent virus from binding to helper t-cells
- disrupt reverse transcriptase
- inhibit assembly of new viruses
- drug treatment: AZT, retrovir, protease inhibitors, fusion inhibitors, tenofovir.
