post-midterm quiz 1 Flashcards
Innate immunity
nonspecific, primary immunity.
no memory, limited diversity of response (mast cells only)
*short lag time
(mechanical barriers/phagocytotic cells/inflammation)
Adaptive immunity
via lymphoid system! (lymphocytes and antibodies)
HIGHLY specific, has memory,
wide diversity (via somatic recombination - “isotype switching”)
- long lag time
humoral immunity
“long distance immunity”
antigens secreted into blood
*target site can be far from origin
B Lymphocytes!!!
cellular immunity
“short distance immunity”
= in precise area of “target”
T Lymphocytes!! (T helper and cytotoxic T cells)
primary lymphoid organ
where lymphocytes develop
(up to self-tolerance, not yet immunocompetent
thymus (T cells) Bone marrow (B cells)
secondary lymphoid organ
“organs” where mature lymphocytes accumulate and reside.
ie: MALT, tonsils (palatine/lingual/pharyngeal), spleen
site of antigen-independent proliferation of lymphocytes
Thymus (T cells) or Bone Marrow (B cells)
primary lymphoid organs
site of antigen DEpendent proliferation for lymphocytes
secondary lymphoid organs
clonal expansion
activation (and proliferation) of lymphoctyes stimulated by binding antigens,
increase number of “clones” (cells from same cell line)
*in secondary lymphoid organs
clonal selection
limiting the number of active clones by binding foreign antigens,
*in secondary lymphoid organs
Effector cells (for lymphocytes)
cells that remove the bound antigen from the body.
B cells: plasma cells
T cells: cytokines, …
basis of acquired immunity
Memory cells!
made at 1st exposure, fast response at 2nd exposure.
–> differentiate into effector cells w/ exposure
IgA antibody
in tears, saliva, gut lumen, milk.
–> passive immunity to newborn through milk!
forms dimers
(decent for agglutination)
IgD antibody
B lymphocyte surface receptor
IgE antibody
binds to mast cells, basophils, eosinophils.
- for allergic reactions and defense against parasitic infections
- -> triggers degranulation of mast cells!
IgG antibody
most abundant,
in blood and tissue fluids.
*can cross placental barrier!
binds to macrophages and neutrophils
IgM antibody
B lymphocyte surface receptor,
* forms pentamers in blood!
(good for agglutination)
agglutination
formation of large antigen-antibody complexes
opsonization
coating surface of antigen with antibodies,
marks for disposal by neutrophils, macrophages.
antigen presenting cells
cells that express MHCII and can activate T helper cells
- macrophages
- dendritic cells
- B lymphocytes
types of T cells
- T helper cells
- Cytotoxic T cells
- NK cells (“natural killer”)
- regulatory T cells (“TRegs”) – suppress immune system activation
HEV (high endothelial venule)
specialized post-capillary venules in paracortex of lymph node(s),
where lymphocytes enter the node from blood.
Epithelial reticular cells
= the cytoreticulum in cortex and medulla of thymus,
* unique to thymus (no other organ has ERC!)