The Lymphatic System & Body Defenses, Chapter 12
Which of the following is NOT involved in acute hypersensitivity?
Cytokinins
What type of T cell directly attacks infected cell?
Cytotoxic T cells
Which of the following is NOT found in high concentration in pus?
Cytotoxic T cells
A person who has recovered from mumps is pretected from contracting the disease again by a ________.
secondary humoral response
HIV, the virus that causes AIDs, targets and destroys__________.
Helper T cells
Which cells stimulate the antibody-secreting cells & cytotoxic T cells?
Helper T cells
The adaptive, or specific, defense system mounts the attack against particular foreign substances. When lymphocytes themselves defend the body, the immunity is called call-mediated immunity because the protective factor is living cells.
Humoral Immunity: -Protection by antibodies -Can be actively or passively acquired Cellular Immunity: -Protection by living cells Both: -Antigen-Specific -Systemic Immunity -Development of self-tolerance
What antibody class is most abundant in plasma, is important in fixing complement, & crosses the placenta to provide protection to a newborn?
IgG
What class of antibodies functions as antigen receptors on B cells & form large complexes that can agglutinate cells?
IgM
What happens to the fluid filtered from blood capillaries?
It enters lymphatic vessels & is returned to the bloodstream.
What is the function of natural killer (NK) cells?
Killing virus infected, cancer, or foreign graft cells.
What tissue or organ filters lymph?
Lymph nodes
What structure are major components of the lymphatic system?
Lymphatic vessels & lymphoid tissues/organs.
Found in the walls of the small intestine, _____ capture(s) & destroy(s) bacteria before they invade the intestinal wall.
Peyer's patches
The lymph nodes help protect the body by which of the following?
Producing lymphocytes
Each of the following is involved in the formation of antibodies EXCEPT _______.
Supressor T cells growing & dividing very rapidly
How do antibodies help phagocytes remove soluble foreign antigens?
They bind to soluble antigens so that those antigens precipitate out of the solution.
How do phagocytic cells protect the body from invading pathogens?
They remove & destroy pathogens that breach the membrane barrier.
The injection of weakened pathogens to produce immunity is a(n) _______.
Vaccinations
What type of immunity do vaccines provide?
active, artificially acquired immunity
Proteins secreted by plasma cells that bind to specific pathogens are called ________.
antibodies
What is humoral immunity?
antibody-mediated immune response
What are the substances that activate the immune system called?
antigens
What condition occurs when the body makes antibodies against self-antigents?
autoimmune diseases
What lymphoid organ produces hormones that direct the maturation of T lymphocytes?
thymus
Why are the elderly more susceptible to infection & cancers?
because the efficency of the immuneresponse decreases in old age
During an inflammatory response, histamine is released. This causes blood vessels to _______ and pain receptors to be activated.
dilate
Which infammatory process is triggered by histamine?
dilation of vessels
The keratinized ____ and the _____ are the body's first line of defense against pathogens.
epidermis; mucous membranes
Which of these is found on the surface of an antigens-presenting cell (APC)?
fragment of forign pathogens ingested by the cell
A penicillin reaction is a life- threatening even. In those who are allergic to penicillin, the drug acts as a ________ that binds to blood proteins, causeing a strong immune response.
hapten
What is the benefits of a moderate fever?
inhibits bacterial growth
The substance produced by virus-infected cells that help other cells resist viral infection is ________.
interferon
Which of the following is NOT an autoimmune disease?
lung cancer
An infection commonly causes swelling & tenderness of the _______.
lymph nodes
What is the function of histamine?
triggers inflammatory response
Monoclonal antibodies are commercial preparation of a pure antibody that reacts to a single antigen. Which of these are example of current uses of monoclonal antibodies?
-Deliver drugs to fight cancer -Early cancer diagnosis -diagnosis pregnancy
In order to be part of cell-mediated immunity, lymphocytes must mature from the naive form in which they are produced to ummunocompetent cells ready to act against antigens. Where does this occure?
-Red bone marrow: site where B cells gain immunocompetent -Thymus: site where T cells gain immunocompetence -Red bone marrow: site where immature (naive) lymphocytes are produced -Circulation: site where only self-tolerated cells are found -Circulation: site where antigens-activated immunocompetent cells respond. -Lymphoid Tissues: site where lymphocytes encounter antigens & activate.
Unlike B cells, T cells are not able to bind with free antigens. Instead the antigens must be "presented" by an APC and a double recognition must occur. T cells are a diverse family of related cells derived from a progenitor that have different functions in cell-mediated immunity.
-Regulatory T cell: slows the T cell response once the antigens has been controlled. -Memory T cells: circulates throughout the body for a foreign antigen it has seen before. -Helper T cell: binds to microphage & processed antigen in a double recognition step. -Cytotoxic T cell: recognizes viral protein on the surface of an infected cell and releases perforins and granzymes.
Effects of Aging on Immunity? As with many other body systems, immune system function decreases with age. Which of the following statements describe(s) the effects of aging on immunity?
-The chance of developing an autoimmune disease increases. -Cancer becomes more common.
Cells that specialize in killing virus-infected, cancerous, or foreign graft cells are called cytotoxic, or killer, T cells. How do they carry out their function?
1)Cytotoxic T cell binds antigen 2)Perforins are released 3)Pores are formed in target membranes 4)Granzymes digest target components. 5)Cytotoxic T cell detaches
The major role of APC's in immunity is to engulf antigens and then present fragments of them, like signal flags, on their own surfaces where they can be recoginized by T Cells. Antigen presentation is essential for activation & clonal- selection of the T cells.
1)Macrophages, Dendritic cells & B lymphocytes bind directly to free antigens. 2)Macrophages & Dendritic cells activate helper T cells. 3)B lymphocytes & T lymphocytes respond to specific antigens 4)Macrophages & Dendritic cells eat & present antigens to other cells.
What is the function of antigen-presenting cells (APCs)?
Activating T lymphocytes
What role do plasma cells play in the immune response?
produces antibodies into body fluids
What 2 cell types provides humoral & cell-mediated immunity against specific foreign antigens?
B & T Lymphocytes
What is the function of complement proteins?
Binding to foreign cells & punching holes in their surfaces.
