Components of the Immune System Flashcards
The immune response is ___ based.
cell
What do all immune cells develop from?
hematopoietic stem cells
What determines what hematopoietic stem cells will develop into?
cytokines and growth factors
What can stem cells differentiate into?
- myeloid progenitors
- lymphoid progenitors
What are examples of myeloid progenitors?
- granulocytes
- monocytes
- macrophages
- mast cells
What are examples of lymphoid progenitors?
- lymphocytes
- natural killer cells
- dendrite cells
What are granulocytes?
contain cytoplasmic granules which have compounds in them that are released during an immune response to kill pathogens
What are the types of granulocytes?
- neutrophil
- eosinophil
- basophils
- mast cells
What do neutrophils do?
- perform phagocytosis, engulfing and breaking down and killing the pathogen
- first responders from bloodstream at site of infection
What are neutrophils called in birds?
heterophils
What do eosinophils do?
release cytoplasmic granules to kill parasites
What do basophils do?
release cytoplasmic granules in response to parasites
How are mast cells different from other granulocytes?
are not white blood cells
Where are mast cells found?
within tissues
What do mast cells do?
release cytoplasmic granules in response to parasites and infection
What do granules of mast cells contain?
histamine
What does histamine do?
increases permeability of blood vessels
What are the types of agranulocytes?
monocytes and lymphocytes and dendrite cells
What do monocytes do?
migrate into tissues at site of infection and differentiate into a cell called a macrophage
What are the two types of macrophages?
monocyte-derived and resident tissur
What are monocyte derived macrophages called?
inflammatory macrophages
Where do resident tissue macrophages come from?
embryonic cells
What are the types of resident tissue macrophages?
- microglia
- osteoclasts
- kupffer cells
- alveoler macrophages
Where are microglia found?
nervous system
Where are osteoclasts found?
bone
Where are Kupffer cells found?
liver
Where are alveolar macrophages found?
lungs
What do resident tissue macrophages do?
fight infection but also clear any damaged tissue
What do macrophages do?
perform phagocytosis
How are macrophages different than neutrophils?
has antibody receptors and when an antibody binds to an antigen it marks that antigen for phagocytosis by macrophagesW
What is the marking of an antigen for phagocytosis by macrophages called?
opsonization
What is the antibody that binds to an antigen for opsonization called?
opsonin
Where are dendrite cells found>
in different tissues
What can dendrite cells do?
perform phagocytosis on antigens and pathogens
What are macrophages and dendrite cells classified as?
professional antigen presenting cells (professional APCs)
What do professional antigen presenting cells do?
- form a “bridge” between the innate and adaptive immune response
- phagocytize antigens, break the antigen down, and present pieces of the antigen on their cell membrane
What activates helper T-cells?
binding to antigen presenting on the professional APCs
What are the two types of lymphocytes?
T and B cells
What are clusters of differentiation?
protein expressed on cell surfaces, use these to differentiate between types of lymphocytes
What do each B and T cell have?
antigen specific receptors
What receptor do B lymphocytes express?
B-cell receptors
What receptor do T lymphocytes express?
T-cell receptors
When are receptors generated for B and T cells?
during development
What are naïve lymphocytes?
mature fully developed lymphocytes that haven’t encountered the antigen they are specific for
What happens when lymphocytes are engaged by the antigen they are specific for?
get activated, go through clonal selection, and then differentiate into one of two types of cells
What type of cells do lymphocytes that have gone through clonal selection differentiate into?
most effector cells, some memory cells
What do effector cells do?
carry out specific functions to combat the pathogen
What do memory cells do?
stay around for secondary response
T cell receptors only recognize ___
antigens bound to another cell
What are the structures on antigen presenting cells called?
major histocompatibility complexes
What are the two types of major histocompatibility complexes?
class one and class two
Where are class one MHC found?
on all nucleated cells in body
Where are class two MHC found?
expressed only by professional APCs
What are the two types of T cells?
cytotoxic T-cells and helper T-cells
How can cytotoxic T cells be differentiated?
CD8
What will the T cell receptor on cytotoxic T cells recognize?
antigen bound to MHC class one
What do cytotoxic T cells do?
kill virally infected cells
What do helper T cells express, for differentiation?
CD4
What do t cell receptor recognize for helper t cells?
recognize antigen bound to MHC class two
What are subsets of helper t cells?
- TH 1 and TH 17
- TH 2 and TFH
- regulatory T cells
What do TH1 and TH17 do?
regulate immune response to intracellular pathogens
What do TH2 and TFH do?
help with extracellular pathogens
What do regulatory T cells do?
have capacity to inhibit immune response and involved in inhibition of autoimmunity (so body doesn’t react to itself)
how are regulatory T cells differentiated?
express CD4 and CD 25
What is the B cell receptor on B cells like?
membrane bound antibodies
What happens when B cell recognizes antigen?
B cells undergo clonal selection and generate effector cells called plasma cells and also generates some memory cells
What are plasma cells?
activated B cells
What do plasma cells do?
secrete antibodies
Are natural killer cells antigen specific?
no
What do natural killer cells do?
kill virally infected cells
What are primary lymphoid organs?
locations where immune cells develop and mature
What are the primary lymphoid organs?
bone marrow, thymus, and bursa of fabricus
What does bone marrow develop?
b-cell development (in mammals)
What does thymus develop?
T-cell development
What does bursa of fabricus do?
b-cell development (in birds)
What are secondary lymphoid organs?
locations where adaptive immune response is initiated
- aka where lymphocytes are activated
What are the secondary lymphoid organs?
- lymph nodes
- spleen
- mucosa associated lymphoid tissue
What are lymph nodes involved in?
activation due to antigen in tissues
What is the spleen involved in
activation due to antigen in blood
Where are mucosa associated lymphoid tissues found?
along in mucosal membranes
What are mucosa associated lymphoid tissues?
barriers for antigen entering body
What are the types of mucosa associated lymphoid tissues?
- GALT
- BALT
- NALT
- SALT
Where is GALT found?
GI tract
Where is BALT found?
bronchus
Where is NALT found?
nasal
Where is SALT found?
skin
What are tertiary lymphoid organs?
site of infection