Chapter 17 Part 1 Flashcards
what is the characteristic of innate immunity?
first line of defence
- rapid response (within hours)
- non-specific
- response remains constant
- does not require previous exposure
what is the characteristic of adaptive immunity?
requires time to gear up
- slow (days to weeks)
- gradually improves
- highly specific
- holds memory of previous exposure
what is the origin to the cells called?
hematopoietic stem cell
What is the lymphatic system?
attached to the circulatory system, collects interstitial fluid and scans for forgien pathogens then returns it back to the circulatory system
What are monocytes?
they are the precursor to macrophages that circulates it in the blood stream until they are needed, they will migrate to tissue and becomes macrophages
what are marcophages?
there are many types an they live in the tissue.
they have pattern recognition receptors to recognize the PAMPs on pathogens and release cytokines
What do macrophages do?
they are the FIRST line of cellular defence (innate)
they are antigen presenting cells
- secrete cytokines
- they eat (phagocytosis) pathogen
- present pieces of the pathogen in Class 2 MHC molecules to Helper T cells
what are PAMPs?
pathogen associated molecular patterns
What are neutrophils and what do they do?
released by bone marrow to circulate in bloodstream (innate)
- when signalled by cytokines they enter tissues
- they kill (phagocytose) pathogens
How does neutrophil kill pathogens?
- they have granules that contain lytic and bactericidal substances to kill the pathogen when phagocytosed
- when they can’t phagocytose anymore, they spit out neutrophil extracellular traps (NETs) to catch remaining pathogens
what is leucoytosis?
the increase in the number of circulating neutrophils
- used to determine infection
what happens to neutrophils that can’t phagocytize anymore?
after casting their NET, they get phagocytosed by macrophage
What are dendritic cells?
they are cells that phago and pinocytose pathogens and present antigen in both Class 1 and 2 molecules to T cells when they enter lymph nodes
- bridge between innate and adaptive immune systems
What is cross presentation?
when a cell (specifically dendritic cells) can present antigen in both class 1 and 2 MHC molecules
What are the primary lymphoid organs?
- bone marrow
- thymus
What is an antigen?
a molecule or fragment of pathogen that is recognized by an antibody, a B-cell receptor or can be bound in a MHC molecule and presented to the T cell
What is a epitope and what is its other name?
antigenic determinant
- its the apart of the antigens that the antibody binds to or the part that gets recognized by a T cell receptor when presented in a MHC molecule
What is a cytokine?
a substance that is secreted by immune cells that affects other immune cells
What is a chemokine?
it is a type of cytokine that induce directed chemotaxis
what are the types of T cells?
- helper T cell (CD4+)
- cytotoxic T cells (CD8+)
what does cytotoxic T cells do?
(CD8+) they kill virus infected cells
what does helper T cells do and what receptor do they have on them?
(CD4+)
- regulate activities of other white blood cells
- help activate macrophages, B cells and cytotoxic T cells
What are natural killer cells?
- part on innate, they circulate the blood and contain toxic granules
- do not have antigen specific receptors
they are cells that induce virus infected cells to undergo apoptosis
where do B cell mature?
bone marrow
where do T cell mature?
thymus
Class 1 MHC is associated with… AND are found…
CD8+ and on every nucleated cells
Class 2 MHC is associated to with… and are found…
CD4+ and only found on professional antigen presenting cells (dendritic, macrophage and B cells)
What does the B cell antigen Receptor do?
it gets secreted as an antibody after activation and differentiation
what does the T cell antigen receptor do?
it recognizes antigens bound to a MHC molecule on a antigen presenting cell
What are the antigen presenting cells?
- macrophage
- dendritic cell
- B cell
What counts as a white blood cells?
monocytes (precursor macrophages) and lymphocytes (precursor T and B cells)
What is a lymphocyte?
T and B cells that have not undergone differentiation yet
what does MHC stand for and why are they synthesized?
Major Histocompatability Complex protein and are synthesized in the ER
what is the difference between CD4+ & CD8+ receptors?
CD8+ has an extra alpha and beta receptor and CD4 doesn’t
