Chapter 22: Immunity Flashcards
leukocytes include 3 types of granulocytes:
1- neutrophil
2- basophil
3- eosinophil
leukocytes include 2 types of agranulocytes:
1- monocyte
2- lymphocyte
monocytes
become macrophages when they leave blood and enter tissues
lymphocytes consist of
1- B-lymphocytes
2- T-lymphocytes
3- Natural Killer Cells
most leukocytes are in ___________ ___________
body tissues
secondary lymphoid structures
- lymph nodes
- spleen
- tonsils
connective tissue houses ________ cells
mast
secondary lymphoid structures house ______________, _______________, ______________, ______________, and ____________________
- B-lymphocytes
- T-lymphocytes
- NK cells
- macrophages
- dendritic cells
select organs house ______________
macrophages
skin and mucosal membranes house _________________
dendritic cells
connective tissue throughout the body house _______________
mast cells
IL
interleukin
Indigenous microbiota
friendly bacteria
cytokines
small proteins that regulate immune activity
effects of cytokines
- signaling cells
- controlling development and behavior of immune cells
- regulating inflammatory response
- destroying cells
two categories of the immune system
1- innate immunity
2- adaptive immunity
innate immunity
- present at birth
- nonspecific
- protects against a variety of different substances
adaptive immunity
- acquired/specific immunity
- response to antigen involves specific B and T-lymphocytes
- takes several days to be effective
1st line of defense
includes barriers of skin and mucosal membrane (prevent entry); innate immunity
2nd line of defense
nonspecific cellular and molecular internal defense; innate immunity
3rd line of defense
specific T- and B-lymphocytes; adaptive immunity
mucous membranes
line body openings
mucous membranes produce _______ and release ________________ ______________
mucus/ antimicrobial substances
neutrophils
- most prevalent leukocyte in blood
- first to arrive during the inflammatory response
- phagocytic
macrophages
- reside in tissues throughout the body
- arrive later and stay longer than neutrophils
dendritic cells
destroy particles and then present fragments
___________ are presented on dendritic cell surface to T-lymphocytes
antigens
heparin is a
coagulant
basophils and mast cells promote ______________
inflammation
basophils ___________ in the __________ while mast cells reside in _______________ ________, _________, and ____________ _________
circulate in the blood/ connective tissue, mucosa, internal organs
basophils and mast cells release ____________ containing chemicals
granules
basophils and mast cells attract __________ cells
immune
histamine
increases vasodilation and capillary permeability
basophils and mast cells attract chemotaxis chemical such as ___________ and ____________
histamine and heparin
NK (natural killer) cells
destroy unhealthy/unwanted cells by releasing cytotoxic chemicals
NK cells accumulate in ____________ ___________ __________
secondary lymphoid structures
cytotoxic chemicals released by NK cells
perforin and granzymes
perforin
creates a transmembrane pore in an unwanted cell
granzymes
enter pore and cause apoptosis of cell
interferons (IFN)
a class of cytokines that nonspecifically interferes with spread of intracellular pathogens
interferons bind to ______________ cells and prevent their infection
neighboring
interferons interfere with
viral replication
interferons stimulate _____________ and _______________ to destroy virus-infected cells
NK cells and macrophages
complement system
group of over 30 plasma proteins
effects of activated complement
- inflammation
- opsonization
- cytolysis
inflammation
enhanced by a complement
- activates mast cells and basophils
- attracts neutrophils and macrophages
opsonization
complement protein (opsonin) binds to pathogen
- enhances the likelihood of phagocytosis of pathogenic cell
cytolysis
complement triggers splitting of target cell
- complement proteins form a membrane attack complex (MAC) that creates a channel in the target cell’s membrane
- fluid enters causing cell lysis
chemotaxis
attracted to wound/inflammation
diapedesis
makes opening in blood vessel
inflammation
an immediate response to ward off unwanted substances
- local, nonspecific response of vascularized tissue to injury, infection
cardinal signs of inflammation
- redness
- heat
- swelling
- pain
- loss of function
fever (pyrexia)
abnormal body temperature elevation
a fever is considered
1℃ or more from normal 37℃
fever results from
release of pyrogens (interferons)
benefits of fever
- inhibits reproduction of bacteria and viruses
- promotes interferon activity
- increases activity of adaptive immunity
- accelerates tissue repair
Ig
immunoglobulin
pus is
exudate
pus contains
- destroyed pathogens
- dead leukocytes
- macrophages
- cellular debris
If pus isn’t completely cleared, it may form an
abscess
adaptive immunity is the ____ line of defense
3rd
adaptive immunity involves
specific lymphocyte responses to an antigen
immune response consists of
lymphocytes and their products
two branches of adaptive immunity
1- cell-mediated immunity
2- antibody-mediated/humoral immunity
cell-mediated immunity
involving T-lymphocytes; antigens within cells
antibody-mediated immunity (humoral immunity)
involving B-lymphocytes, plasma cells, and antibodies; antigens outside of cells
adaptive immunity is a ________________ ______________ to a pathogen
customized response
antigen
substance that binds a T-lymphocyte or antibody
antigen is usually a
protein or a large polysaccharide
B-lymphocytes
make direct contact with antigen
T-lymphocytes
- managers
- must have antigen processed
antigens are _______ _____
name tags
cytokine
chemical messenger that is released by immune system cells
plasma cells
activated B-cells
- produce antibodies
helper T-cells
captains/managers
CD4 is found on
T-helper cells
CD8 is found on
cytotoxic T-cell
T-lymphocyte subtypes
- helper T-lymphocytes
- cytotoxic T-lymphocytes
helper T-lymphocytes (Th)
help activate B-lymphocytes and other immune cells
- contain the CD4+ in plasma membrane
- investigates MHC II antigens
cytotoxic T-lymphocytes (Tc)
release chemicals toxic to cells
- contain CD8 in the plasma membrane
- investigates MHC I antigens
TCR
T-Cell Receptor
- “hitch”
BCR
B-Cell Receptor
- how the B-cell gets its leads
IgD
helps find antigens or things to investigate
MHC I
found on ALL nucleated cells
MHC II
are found on APCs only; safe antigen holder
Antigen Presentation
cells display antigen on plasma membrane so T-cells can recognize it
2 categories of cell present antigens
1- all nucleated cells present antigens
2- antigen-presenting cells (APCs)
antigen-presenting cells (ACPs)
immune cells that present to BOTH helper T-cells and cytotoxic T-cells
- include:
- dendritic cells
- macrophages
- B-lymphocytes
antigen presentation requires attachment of antigen to ___________
major histocompatibility complex (MHC)
MHC
a group of transmembrane proteins; antigen holder
formation of lymphocytes occurs in
primary lymphoid structures (red bone marrow and thymus)
activation of lymphocytes in
secondary lymphoid structures they are exposed to antigen and become activated
- replicate to form identical lymphocytes
T-lymphocytes migrate to
site of infection
B-lymphocytes stay in
secondary lymphoid structure as plasma cells
T-lymphocytes originate in
red bone marrow
SCID
severe combined immunodeficiency disease
formation of T-lymphocytes
- originate in red bone marrow
- migrate to thymus as pre-T-lymphocytes to complete maturation
- initially have both CD4 and CD8 proteins
- possess unique TCR produced randomly
- each cell has its TCR “tested” through a process of selection
effector response
action of lymphocytes to eliminate antigen
effector responses of T and B-lymphocytes
- T-lymphocytes: migrate to site of infection
- B-lymphocytes: stay in secondary lymphoid structure
first signal of the activation of cytotoxic T-lymphocytes
- direct contact between TCR of cytotoxic T-cell and peptide fragment with MCH I molecule
- interaction stabilized by CD8 of cytotoxic T-lymphocyte
second signal of the activation of cytotoxic T-lymphocytes
- other receptors of APC and T-cell interact
- IL-2 released from HELPER T-cells binds to and stimulates cytotoxic T-lymphocytes
activated cytotoxic T-cells proliferate and differentiate
- some become activated cytotoxic T-lymphocytes
- others become memory cytotoxic T-lymphocytes
B-lymphocytes need to be _______________, but can respond to antigens ___________ of cells
activated/outside
first signal of activation of helper T-lymphocyte
direct contact with MHC molecule of APC
the process of the first signal of activation of helper T-lymphocyte
CD4 binds with MHC class II molecule of APC; TCR interacts with antigen within MHC class II molecule
second signal of the activation of helper T-lymphocyte
other receptors of APC and T-cell interact
helper T-cells proliferate, forming clones of helper T-cells
- some cells become activated helper T-lymphocytes, that produce IL-2
- some cells become memory-helper T-lymphocytes, available for future encounters
first signal of the B-lymphocyte activation
free antigen binds to BCR; B-lymphocyte engulfs and presents antigen to activated helper T-lymphocyte
second signal of the B-lymphocyte activation
IL-4 released from activated helper-T-lymphocyte stimulates B-lymphocyte
activated B-lymphocyte proliferates and differentiates to form a clone of _________________ and ________________
plasma cells and memory B-lymphocytes
MHC class II
safe antigen holder
IgD
antibodies are the receptors on a B-cell
proliferates
makes a copy
antibody structure
antigen-binding site is a variable site meaning its customizable
neutralization
smother the pathogen with antibodies
agglutination
making big clumps of bad guys
precipitation
drag down the bad guy making it heavier so it can’t easily move around
five major classes of immunoglobulins
- IgG
- IgM
- IgA
- IgD
- IgE
IgA
- saliva, tears, breastmilk (body secretions)
- protects respiratory and GI tract
IgD
antigen-specific B-lymphocyte receptor (BCR)
IgE
- parasites and allergic reactions
- attracts eosinophils
IgG
- 75-85% of antibodies in blood
- can cross the placenta and cause hemolytic disease in newborns (HDN)
IgM
- found mostly in blood
- large, pentameter structure
- most effective at agglutination
- responsible for rejection of mismatched transfusions
primary response
antibody production for first exposure
secondary response
future exposure to a known pathogen
antibody titer
the amount of antibodies in your blood stream
active immunity
production of memory cells due to contact with antigen
-work, but good for future
naturally acquired active immunity
direct exposure to antigen following entry of the pathogen into the body naturally; get sick
artificially acquired active immunity
antigen exposure from vaccine
passive immunity
no production of memory cells; antibodies from another person or an animal; obtained from another individual
naturally acquired passive immunity
transfer is mother to child across the placenta or in breast milk
artificially acquired passive immunity
transfer of serum containing antibodies from another person or animal
acute hypersensitivity (allergy)
exaggerated response of immune system to a noninfectious substance, or allergen
allergen examples
pollen, latex, peanuts
allergic asthma
labored breathing and coughing
hives
red welts and itchy skin
