unit 11 (lymphatic) Flashcards
lymph
-runs alongside veins
-excess tissue fluid
-edema if fluid isn’t picked up
-one way system from capillary bed to lymph nodes to venous return system to blood (only toward heart)
lymph nodes
filter lymph before it’s returned to blood
spleen
-forms blood cells in fetus
-acts as blood reservoir
-filters and cleans, lymphocyte proliferation, destroys worn out RBC
-left side of abdomen
thymus
site of training for t lymphs
-overlying heart
Peyer’s patches
macrophages capture and destroy bacteria in the intestine
-walls of small intestine
tonsils
trap and remove bacteria
-throat opening of nose, mouth, and tongue
mucosa associated lymphoid tissue
appendix; acts as a sentinel to protect respiratory and digestive tracts
innate defense (nonspecific)
protects against wide varieties of invaders
adaptive defense system (specific)
fights invaders that get past innate; highly specific resistance to disease: immunity
examples of innate
surface membrane barriers
cellular
chemical defenses
fever
surface membrane barriers
intact skin and mucous membrane; first line of defense; acidic skin secretions, sebum, mucus, gastric juices, saliva and tears
cellular
second line of defense; natural killer cells and phagocytes; fever, inflammatory response, Chemicals that kill pathogens, and fever
chemical defenses
antimicrobial proteins
fever
pyrogens and hypothalamus
major steps of inflammatory response
-redness, heat, pain, swelling
-damaged cells release chemicals
-cause: phagocytes and WBC to move into area
-prevents: spread, disposes debris and pathogens, beings repair
complement
at least 20 plasma proteins circulating in plasma; form MAC’s and produce holes in cells for water to rush in
interferon
virus infected cells secrete these; bind to membrane receptors on healthy cells to interfere with ability of viruses to multiply
how a fever protects the body
-speeds repair processes (inc in temp)
-hypothalamus regulates body temp by pyrogens
-high temps inhibit release of zinc and iron that bacteria needs
humoral immunity
antibody mediated immunity; body fluid and B cells
cellular immunity
cell mediated immunity; virus -infected cells, cancer cells, cells of foreign grafts (target these)
antigen
any substance capable of exciting immune system and provoking an immune response
hapten
incomplete antigens; not antigenic by themselves; poison ivy, animal dander, detergents, hair dyes, and cosmetics
b lymphocytes
produce antibodies and oversee humoral immunity; bone marrow; can bind to specific antigen and make copies of themselves
t lymphocytes
cell mediated; mature in thymus; do not make antigens; APC
importance of antigen-presenting cells
engulf antigens and present fragments on their cell surfaces to be recognized by t cells
examples of APC
dendritic cells, macrophages, b lymphs
B and T lymphs
migrate to lymph node and spleen; thymus and bone marrow; self-tolerance=education
plasma cells
produces antibodies to destroy antigens
memory cells
T cells; clones
antibodies
activity lasts 4-5 days; blood protein (gamma globulin); secreted by activated B cells; have different classes
active immunity
occurs when B cells encounter antigens and produce antibodies; naturally acquired during bacterial and viral infections; artificially acquired from vaccines
passive immunity
antibodies from someone else (infusion, breast milk); short lived and no memory
general structure of antibody
protein
5 classes of antibodies
IgM
IgA
IgD
IgG
IgE
IgM
can fix complement
IgA
found mainly in secretions (mucus or tears)
IgD
important in activation of B cells
IgG
can cross placental barrier and fix complement (most abundant antibody in plasma)
IgE
involved in allergies
neutralization
antibodies bind to specific sites on exotoxins or viruses to cause cell injury
agglutination
antibody - antigen reaction that causes clumping of cells
precipitation
cross-linking reaction in which antigen-antibody complex settles out of solution
helper
recruit other cells to fight; B cells to make antibodies since T cells can’t
regulatory
help slow down immune response; release chemicals to stop press activity of b and t cells
cytotoxic
killer cells; insert toxic chemicals
autografts
tissue transplanted from one site to another on same person
isografts
tissue grafts from a genetically identical person (twin)
allografts
tissue taken from a person other than identical twin (most common)
xenografts
tissue taken from a different animal species (never successful)
allergies
(immediate and delayed hypersensitivity, anaphylactic shock) the immune system overreacts to an otherwise harmless antigen and tissue damage occurs
autoimmune diseases
occur when body’s self-tolerance breaks down - body produces auto-antibodies and sensitized t lymphs that attack its own tissues
immunodeficiencies
may be congenital or acquired; result from abnormalities in any immune element
SCID
cogenital
AIDS
caused by a virus that attacks and cripples they helper T cells
lymphatic vessels
have valves
thin walls
need skeletal muscles to move lymph
(similar to veins)
third line of defense
antigen and antibody
-antigen specific
-systemic
-memory
antigen specific
the adaptive defense system
recognizes and acts against particular foreign substances
systemic
immunity is not restricted to the initial
infection site
memory
the adaptive defense system recognizes
and mounts a stronger attack on previously encountered pathogens
