Overview of the Immune System (Part 1) Flashcards
different pathogens require ________ immune responses
different pathogens require different immune responses
what type of immune response do viruses use?
intracellular
what type of immune response do bacteria use?
extracellular
what are 2 difference btwn intracellular and extracellular pathogens with respect to the immune system?
- difference in processing
- difference in type of response
what are the 2 types of immune systems used by vertebrates?
- innate immunity
- adaptive immunity
what are the 3 types of major players involved in the immune response?
- organs + tissues
- cells
- molecules
what are the 4 main types of tissues of the immune system?
- bone marrow
- thymus
- lymphatic system
- lymph nodes
do immune cells stay in one part of the body all the time?
no, they travel throughout the body
what occurs at the primary/central lymphoid organs?
immune cells develop
what are the 2 primary/central lymphoid organs?
- bone marrow
- thymus
what occurs at the secondary/peripheral lymphoid organs?
immune cells activate and initiate immune response
what are the 4 secondary/peripheral lymphoid organs? which one is the main one?
- lymph nodes
- spleen
- Mucosal Associated Lymphoid Tissue (MALT)
- other diffuse and loosely organized areas
lymph nodes are main one
how are the secondary/peripheral lymphoid organs connected?
by the blood and lymphatic circulatory systems
do innate and adaptive immunity use the same cells?
some are the same, some are different
what are the 3 main cells in innate immunity?
- neutrophils
- mast cells
- monocytes
what are the 3 main cells in adaptive immunity?
- B cells
- T cells
- T regulatory cells
what are the 3 types of cells involved in both innate and adaptive immunity?
- macrophages
- dendritic cells
- NK cells
immune cells are aka _________ and _________
immune cells are aka leukocytes or WBC
where do all immune cells originate?
in the bone marrow
what type of cell do all mature blood cells arise from?
hematopoietic stem cell (HSC)
what is hematopoiesis?
the process by which HSC differentiate into mature blood cells
where does hematopoiesis occur?
bone marrow
HSCs are _________
pluripotent
what does pluripotent mean?
can generate almost every cell type
what are the 2 main lineages for the origins of immune cells?
- lymphoid
- myeloid
what type of cell derives from HSC for the lymphoid lineage?
common lymphoid progenitor
what type of cell derives from HSC for the myeloid lineage?
common myeloid progenitor
what type of cell is ILC?
NK cells
where do immune cells go after they are produced (3)?
- reside in tissues/organs
- blood
- lymphatic system
what are the 7 types of cells produced by the myeloid lineage
- RBCs
- Granulocytes
- Megakaryocytes
- Monocytes
- Macrophages
- Neutrophils
- Immature dendritic cells
what is the role of RBC in the immune system?
generate antimicrobial compounds
what are 4 types of granulocytes and their function?
- NEUTROPHILS: direct harm to pathogen
- BASOPHILS: inflammation, allergies
- MAST CELLS: inflammation, allergies
- EOSINOPHILS: antiviral, antiparasitic
what determines which granulocyte is used?
depends on the type of pathogen
what is the role of megakaryocytes?
produce platelets for clotting
what happens to monocytes once they are produced?
they migrate into tissues and differentiate into macrophages
what is the main role of macrophages and neutrophils?
phagocytosis
what is another function of macrophages besides phagocytosis?
antigen presentation to T cells
what do immature dendritic cells do?
capture antigen –> mature –> migrate –> present antigen to T cells
what are the most potent antigen-presenting cells for activating T cells?
dendritic cells
why are dendritic cells known as the bridge btwn innate and adaptive immunity?
they are involved in detecting infection and activate adaptive immunity
what are the 3 main types of cells that are produced from the common lymphoid progenitor?
- B lymphocytes/B cells
- T lymphocytes/T cells
- NK cells
what are clusters of differentiation?
lymphocytes all look similar but their CD make them different from each other
what type of immunity are lymphocytes responsible for?
adaptive immunity
what allows lymphocytes to be specific?
T and B cells have receptors on their cell surface
what type of receptor is on B cells?
B Cell Receptor
where is the B cell receptor located? (2)
- bound to membrane
- secreted as antibodies
where is the T cell receptor located?
bound to membrane
what does the activation of the innate immune response produce?
signal molecules
what are the 4 roles of signal molecules in the immune system?
- stimulate and direct the adaptive immune responses
- communicate btwn/within cells
- mediate interactions btwn cells
- trigger changes in target cells
what are 5 examples of changes in target cells that are triggered by signal molecules?
- activation
- signaling
- migration
- transcription
- cellular differentiation
what are the 4 main types of molecules in the immune system?
- secreted proteins
- receptors on cell surface
- intracellular signaling molecules, transcription factors
- antigen
what are the 2 types of secreted proteins?
- cytokines
- chemokines
what is the general role of secreted proteins?
cell communication
what is the role of cytokines?
messenger
what is the role of chemokines?
subset of cytokines that recruit specific cells to a site for cell attraction
what are the 2 roles of receptors on cell surface?
- cytokines/chemokines bind to target cells thru receptors
- cells interact with each other thru receptors
what causes intracellular signaling?
many stimuli, including cyto/chemokine binding
describe the steps of how a monocyte can enter the tissue
- monocytes are circulating in blood and rolling along the endothelium
- tissue releases chemokines to recruit monocytes
- monocyte receptors bind chemokines
- monocyte can enter tissue
what is an antigen?
specific molecules that can trigger an immune response
what are most antigens made of?
protein
what are 5 other things antigens can be made of?
- nucleic acid
- polysaccharide
- lipid
- organic chemicals
- drugs
what is an epitope?
part of an antigen that is recognized by a receptor on an immune cell