I M M U N I T Y Flashcards
functions of lymphatics and lymph nodes
- filtration & immune system activation
- defend body against environmental hazards & internal threats
- immunological recognition
- immune effector functions
- immune suppression
- immunological memory
where does the lymph return to the circulatory system?
- right lymphatic duct
2. thoracic duct
what mechanisms keep lymph flowing through the lymph valves?
- mini valves
- pulsations of nearby arteries
- contraction of smooth muscle in walls of lymphatic vessels
- breathing
- pumping of skeletal muscles
what major cell type is in the red pulp of the spleen?
RBCs & blood borne pathogens
what major cell type is in the white pulp of the spleen?
lymphocytes
describe the non-specific defense, fever
- abnormally high body temperature in response to invading microorganisms
- the body’s thermostat is reset upward in response to pyrogens, chemicals secreted by leukocytes and macrophages exposed to bacteria and other foreign substances
- IL-1 is secreted by macrophages and stimulates hypothalamus to increase temperature set point (called endogenous pyrogen)
describe the non-specific defense, complement
- system of circulatory proteins that assist antibodies in destruction of pathogens
- links innate and adaptive immunity
- amplifies inflammatory response
- membrane attack complex: pore in cell and lyse cell
describe the non-specific defense, interferon
chemical messages that coordinate the defense against viral infections/inhibit viral replication
- virus enters cell and nucleus to replicate (cell is later killed by virus)
- interferon genes switch on
- cell produces interferon molecules
- interferon binding stimulates cell to turn on genes for antiviral proteins
- antiviral proteins block viral production
what changes (or 4 cardinal signs) would occur as a result of inflammation due to histamine increasing blood flow and permeability of blood vessels?
arteriole dilation & local hyperemia
- heat
- redness
increased capillary permeability > capillaries leak fluid (exudate - protein-rich fluid)
- pain
- swelling
MHC 1
displayed by all nucleated cells
recognized by CD8 (cytotoxic T cells)
endogenous antigens
MHC 1 + IL-1 > cytotoxic T cells
(phagocytes, performs, granzymes)
MHC 2
displayed by all APCs (antigen-presenting cells)
recognized by CD4 (helper T cells)
exogenous antigen
APC w/ antigen displayed on MHC 2 + CD4 T cell + B7 to CD28 > T helper cells & T memory cells
how are B cells activated?
B cells are activated by T helper cells + IL-2 > memory B cells and plasma cells
describe an antibody
antigen binding site: variable regions of light and heavy chains
variable region: determines what the antigen binds to
constant region: determines class of antibody
what defense mechanisms do antibodies use to prepare antigens for destruction?
- neutralization
- agglutination
- precipitation
define HIV & discuss its mechanism of infection & its specific target cells
HIV: Human Immunodeficiency Virus
targets CD4 cells via surface proteins/ destroys T helper cells; inject RNA > DNA (reverse transcriptase), DNA > genotype > DNA provirus > viral DNA & proteins that spread
where does HIV reside during the asymptomatic period?
inside helper T cells
after activation, what are the killing actions of cytotoxic T cells (Tc)
directly attack and kill other cells
perforin and granzymes to cause apoptosis
enhance phagocytosis
describe innate immunity
- non-specific
- always present
- physical barriers (skin, mucous)
- phagocytes
- immune surveillance
- interferons
- complement
- inflammation
- fever
describe adaptive immunity
(acquired)
- specific lymphocytes
- specific
- B & T cells
- inducible
define active humoral immunity & artificial/natural elements
when B cells encounter antigens and produce antibodies against them
artificial: vaccine
natural: infection
define passive humoral immunity & artificial? natural elements
instead of being made by plasma cells, ready-made antibodies are introduced into body > B cells not challenged by antigens, immunological memory does not occur, and protection provided by borrowed antibodies ends when they degrade in the body
artificial: injection
natural: placenta
humoral immunity definition
B cells; soluble antibodies, simple, interact in extracellular
cell-mediated immunity definition
T cells: recognize and respond to processed fragment of antigen displayed on cell surface, cell to cell interaction, intracellular abnormal or foreign infected cells
major function of interleukins
IL-2: stimulates fever and is released by macrophages to stimulate T cells to release IL-@ and synthesize more IL-2 receptors
stimulate T cell divisions, attract/stimulate macrophages, attract and stimulate NK (natural killer) cells, promote activation of B cells
