ch 22.2: immunity + defenses Flashcards
immunity
ability to resist and defend against infectious organisms and other damaging substances
immune response
bodys reaction to infectious agents and other abnormal substances
resistance
body’s ability to maintain immunity
types of immunity (2)
innate/nonspecific
adaptive/specific
innate/nonspecific immunity
1st line of defense
- general response to any antigen
adaptive/specific immunity
protects against specific antigens
lymphoctypoiesis
lymphocyte production
types of innate defenses 7
(PPCIIIF)
physical barriers
phagocytes
complement
immune surveillance
interferons
inflammation
fever
physical barriers
keeps hazardous organisms and materials outide the body
-ex, skin and hair
phagocytes
engulf pathogens and cell debris
types of phagocytes
fixed macrophage
- aka histiocytes
reside in specific tissues and organs (ex: bone marrow)
free macrophages
wandering macrophages that travel throughout the body
complement
a system of circulating proteins that assist antibodies in the destruction of pathogens
immune surveillance
the destruction of abnormal cells by NK cells in peripheral tissues
interferons
chemical messengers that coordinate the defenses against viral infections
inflammation
localized tissue level response that tends to limit the spread of an injury or infection
fever
an elevation of body temp that speeds up tissue metabolism and activity of defenses
chemotaxis
when micro and macrophages are attracted or repelled by chemicals in surrounding fluids
adhesion
when a phagocyte attaches to the target and forms a vessicle to internalize it
interferons
small proteins released by activated lymphocytes and amcrophages
types of itnerferons
interferon alpha
interferon beta
interferon gamma
interferon alpha
produced by cells infected with viruses; attracts and stimualtes NK cells
interferon beta
secreted by fibroblasts and slows inflamation
interferon gamma
secreted by T cells and Nk cells and stimulates macrophage activity
most rapid and effective complement pathway
classical pathway
types of complement pathways (3)
classical
lectin
alternative
steps of inflammation
-tissue damage
-mast cell release histamine and heparin activation
- redness, swelling, heat
- phagocyte attraction
- tissue repaid
unwanted effects of inflammation (3)
necrosis
pus
abscess
pyrogen
fever inducing agents that cause the hypothalamus to raise body temp
adaptive defense
specific defense that results from coordianted activities of T and B cells
cytotoxic T cells
attacks antigens physically and chemically
helper T cells
stimulate responses of T cells and B cells
regulatory T cells
moderate the immune response
memory T cells
respond to previously encountered antigens
inflammatory T cells
stimulate regional inflamamtion
supressor inducer T cells
suppress B cell activity
cell mediated immunity
cellular immunity mediated by cytotoxic T cells that defend against abnormal cells and pathogens inside cells
antibody mediated immunity
humoral immunity mediated by B cells that defends against antigens and pathogens in body FLUIDS/humors
active immunity
develops after immune system encounters and antigen and mounts an immune response
naturally acquired active immunity
through environmental exposure to pathogens
artificially acquired active immunity
through vaccines
passive immunity
produced by transferring antibodies from another source
naturally acquired passive immunity
antibodies acquired from the mother or from breastmilk
artificially acquired passive immunity
by an injection of antibodies
inactivated vaccines
contained killed pathogen
live attenuated vaccines
use live weakened forms of the pathogen
mRNA vaccine
stimulate the synthesis of viral proteins that trigger an immune response
subunit, recombinant, polysaccharide and conjugate vaccines
use pieces of pathogen
toxoid vaccines
use altered or weakened forms of bacterial toxins
viral vector vaccines
use modified versions of a different virus to deliver protection
properties of adaptive immunity
specificity
versatility
memory
tolerance
specificity
each T or B cell responds only to a specific antigen and ignores all others
versatility
can recognize a large number of antigens due to lymphocytes and antigens w/ varied antigen sensitivity
memory
some inactive lymphocytes/memory cells stay in circulation after an infection to provide immunity against new exposure
tolerance
the immune system ignores self antigens
how do t cells recognize antigens
by their MHC proteins that serve as signature to identify cells
CD markers
proteins in T cell membranes that provide the molecular mechanism for antigen recognition
cytokines
chemicals released by cells involved in the immune response
B cell sensitization
B cells have specific surface antibodies (B cell receptors)
classes of immunoglobulins/antibodies (5)
IgG
IgE
IgD
IgM
IgA
IgG
80% of all antibodies
can cross placenta
IgE
attaches to the exposed surfaces of basophils and mast cells
- allergy, anaphylaxis,
IgD
antibodies on the surface of B cells/antigen recognition
IgM
first class of antibody secreted/first response
IgA
found primarily in glandular secretions such as mucus, tears, saliva and semen
immunocompetence
ability to produce an immune response after exposure to an antigen
hypersensitivities (allergies)
excessive immune response to antigens
immediate hypersensitivity
rapid and especially severe response to an antigen
