Immune Flashcards
describe nonspecific mechanisms of defense
does not distinguish between infective agents
describe specific mechanisms of defense
responds specifically to particular infective agents
describe an infective agent
anything that is not you that compromises you physiological function
the skin and mucous membranes are ____ defense
nonspecific
the skin and mucous membranes prevents…
entry and spread of microbes to internal spaces
physical barrier
how does the skin and mucous membranes serve as a chemical barrier?
acidic bacterial flora antimicrobial proteins mucous or respiratory tract traps matter stomach acid has low pH that kills almost everything
what kind of respiratory infection is uncommon?
lower respiratory infection
microbes that penetrate the skin or mucous membranes encounter what?
amoeboid WBC
name the 5 types of phagocytic cells
neutrophils monocytes macrophages eosinophils natural killer cells
which kind of phagocytic cell is most common?
neutrophils
where are neutrophils produced?
in red bone marrow
neutrophils have a ______ to site of infection
chemo-attraction
T/F neutrophils are destroyed during response
True
T/F neutrophils are the last to arrive to the site
false
what do monocyte primarily do?
enlarge and come macrophages
what can macrophages do?
amoeboid cells that phagocytize microbes and cell debris
T/F macrophages do not get destroyed
True
where can macrophages be found?
wander or permanently reside in connective tissue or organs
what is the primary immune contribution of eosinophils?
against parasitic worms
what doe natural killer cells destroy?
host’s own cells, abnormal or infected with virus
__________ is a response to tissue damage or entry by microorganism
inflammation
what happens during vasodilation?
increases blood supply and allow WBC to travel to infected area and destroy any bacteria that may be there
T/F dilated vessels are less permeable
False; they are more permeable
the permeable vessels during vasodilation allow…
phagocytes to leave blood and enter tissue
___________ initiate inflammatory response
chemical signals
_________ is released from injured basophils and masts cells in connective tissue
histamines
what can histamines do?
cause vasodilation
what do prostaglandins do?
increase blood flow to injured tissue
describe local inflammation
response confined to a specific area of the body
local inflammation includes…
redness, heat, and swelling and pain because the chemical mediators act on pain receptors
phagocytic cells are attracted to damaged tissue by what?
chemical signal (chemokines)
what is released by leukocytes that cause fever
pyrogens
a fever can inhibit what?
bacterial growth and facilitate phagocytosis
what are antimicrobial proteins?
they are complement proteins that are a part of the innate response
what does the complement system result in?
cell lysis
in the complement system, proteins help split the C3 into….
C3a and C3b
the complement proteins are produced by the _________
liver
the complement proteins circulate in the body in its inactive form, then once it sees a pathogen what happens?
it becomes activated and attaches to it through a chain of activations of other complement proteins
C3b can lead to what?
opsonization
what happens during opsonization?
the complement proteins coat the pathogen which enhances phagocytosis
the C3a can lead to…
inflammation
inflammation stimulates?
histamine release
increased blood vessel permeability
chemotactic attraction of phagocytes
___________ are substances produced in response to virus-infected cells
interferons
regarding interferons, the infected cell ______ be saved
cannot
describe what happens once the infected cell produces an interferon
the interferons diffuse to neighboring cells to promote production of anti-viral proteins so that when a virus tries to infect the neighboring cell, viral replication is prevented
___________ is relatively dormant until your exposed to some pathogen
specific mechanisms of defense
define specficity
recognizes and eliminates particular microorganisms and foreign material that is foreign
during specific response, each lymphocyte only responds to…
one antigen
T/F specific response has self/nonself recognition
true
specific response has the ability to form memory, describe that.
ability to recognize previously encountered antigen
memory is based on what?
production of a clonal population of B cells during initial response
memory cells are _________ during primary response
not active
what activates memory cells?
antigens that have previously been encountered
____________- are the secondary immune response
new clones of effector and memory cells
why do we have memory cells if they are not directly involved in immune response?
they are held in reserve in order to activate a more rapid response
_____ cells are responsible for humoral response
B cells
____ cells are responsible for cell-mediated response
T cells
B cells are formed and mature in
bone marrow
T cells are formed in the
bone marrow
T cells mature in
thymus gland
what is an antigen?
a foreign substance that elicits a lymphatic response that is presented on the surface of bacteria or virus
______ is an antigen-binding immunoglobulin produced by B cells
antibody
________recognize and distinguishes antigens
antigen receptors
antigen receptors are present where?
plasma membranes of lymphcytes
antibodies function as ____ cells
effector
effector cells participate in…
immune response
specificity is determined during….
embryological development
when encountered in the body, antigens are bound by specific lymphocytes, which then…
divide and differentiate
what is created when the specific lymphocytes with bound antigens are separating?
clonal population of effector cells specific to that antigen and the second clonal population of memory cells
name the 2 types of immune responses
primary response
secondary response
the primary response occurs during..
first exposure to antigen
the secondary response occurs when?
encounter a previously encountered antigen
T/F the secondary response has symptoms
false; no symptoms
which response is faster and prolonged and has more antibodies?
secondary response
lymphocytes do not develop antigen receptors against…
body’s own molecules
what is self tolerance?
lack of destructive immune response to the body’s own cells
major histocompatibility complex (MHC) are
unique self markers
glycoproteins embedded in plasma membranes of cells
________ MHC are on every nucleated cell
Class I MHC
Class II MHC are found only…
on specialized immune cells like macrophages, B cells, and activated T cells
Class II MHC can determine if
a cell has the appropriate MHCI
______ response is done if pathogen is found in body fluid
humoral response
the humoral response produces antibodies specific to….
toxins, free bacteria, and viruses present in body fluids
the antibodies of the humoral response are produced and secreted as…
soluble proteins that circulate in blood and lympth
the cell mediated immune response requires…
T cells
what is the response to intracellular infection by virus, bacteria, etc
cell mediated response
activated helper T cells secrete….
cytokines that stimulate other lymphocytes
helper T cells can differentiate into…
activated helper T cells and Memory helper T cells
Antigen-presenting cells (APC) are cells that
take up antigens and present them to their surface
B cells and macrophages ____ foreign material
engulf
__________ bind foreign material and convey it to the outside of the APC
Class II MHC
describe the main process of the cell mediated response
infected cells display antigens complexed with Class I MHC’s
cytotoxic T cells recognize and bind to antigen-MHC complex
Cytotoxic T cells releases perforin which lesions infected cell
infected cell undergoes lysis and dies
pathogen may be destroyed or released to be attacked by antibodies
cytotoxic T cell continues to live and may kill other cells with antigen-MHC complex
define cytokines
are soluble chemicals that will attract other immune cells to site of infection
describe the main process of humoral response
we have a pathogen in the fluid
naive B cells is covered with antigen receptors and encounters a antigen
the naive B cells are activated
clonal division to become plasma cells and memory cells
plasma cells produce antibodies
B cells can’t make memory cells unless…
they have been activated by T cell
T dependent antigens evoke cooperative responses with…
macrophages, helper T cells, and B cells
T/F with T dependent antigens, memory cells are produced
true
T-independent antigens are antigens that trigger
humoral response without macrophages or T cells
T independent antigens stimulate what directly?
B cells
T/F with T-independent antigens, memory cells are produced
False; they are not produced
name the 3 main parts of an antibody
antigen-bound site
complement binding site
macrophage binding site
antibodies are specialized proteins known as _______
immunoglobulins
name the 5 main types of Igs
IgM IgG IgA IgD IgE
IgM is responsible for
circulating, appear during initial response
IgG is for
cross blood vessels, protect against bacteria, viruses, and toxins in blood, trigger complement system
IgA is for
in mucous membrane, prevent attachment of bacteria and viruses to epithelial surfaces also in tears, saliva, and perspiration
IgD is for
found in external membranes of B cells, initiates B cell differentiation
IgE is for
attaches to receptors on mast cells and basophils, stimulates releases of histamine and other chemicals that cause allergic reaction
T/F antibodies directly destroy antigenic pathogen
false, they do not
so what do antibodies actually do?
they tag the pathogen and other mechanisms destroy it
what is neutralization
blocks viral attachment sites by coating it
what is opsonization
bound antibodies tag it to enhance macrophage attachment to it and phagocytosis of microbe
what is agglutination
cross linking of antibodies between adjacent antigens that creates a complex to makes it easier for phagocytes to kill
what is precipitation
cross-link soluble antigen molecules instead of cells
what is complement fixation
antibodies combine with complement system
define active immunity
conferred by recovery from a infectious disease
define passive immunity
transfer of antibodies from one individual to another
define natural active immunity
antigen enters body naturally and body induces antibodies
define naturally passive immunity
antibodies pass from mother to fetus via placenta or to infant via breast milk
define artificially active immunity
antigens are introduced in vaccines and body produces antibodies
define artificially passive immunity
performed antibodies in immune serum are introduced by serum
define allergies
hypersensitivity of the body’s defenses to an environmental antigen
________ is an acute allergic reaction
anaphylactic shock
what happens during anaphylactic shock
mast cell degranulation causes a sudden dilation of peripheral blood vessels and then there is a decrease in blood pressure
name 5 autoimmune diseases
lupus erythematosus rheumatoid arthritis insulin-dependent diabetes multiple sclerosis Grave's disease
immunodeficiency diseases are characterized by
deficient humoral or cell-mediated immune defenses
people with AIDS are susceptible to
opportunistic diseases
viral entry of HIV is dependent on…
CD4 receptor
