Pathology and Immunology Flashcards
what are the four main organs of the immune system
thymus
bone marrow
lymph nodes
spleen
what are the four main organs of the immune system connected by
lymphatic system
where do T cells mature
thymus
what is responsible for making the white blood cells that eventually become lymphocytes
bone marrow
name 3 functions of the lymphatic system
transport clean fluids back to blood
drain excess fluid from tissues
remove debris from cells of body
what are the four stages of inflammation
initiation - response to harmful agents
progression - containment of harmful agents
amplification - modulation of immune response
resolution - healing (acute)/ failure to resolve (chronic)
what innate immune cells are of myeloid origin
mast cells
monocytes/ macrophages
dendritic cells
neutrophils
eosinophils
basophils
what innate immune cells are of lymphoid origin
natural killer cells
innate lymphoid cells (ILCs)
name the function of macrophages/ monocytes
monocytes differentiate into macrophages
macrophages respond early to infection or tissue damage
they phagocytose and present antigen
what are mast cells
granulocytes
best known for role in allergy
what are neutrophils
phagocytic granulocytes
contain numerous granules
what are natural killer cells
they recognise and kill abnormal cells
are important at holding back viruses until the adaptive immunity kicks in
what are innate lymphoid cells
non-cytotoxic natural killer cells
what are dendritic cells
they present antigens
bridge innate and adaptive immunity
activate T and B cells
how do T cells work
they recognise peptides presented by antigen presenting cells through T cell receptor
what is the function of T helper cells
help support other immune cells to fight threats
what is the function of Cytotoxic T cells
destroy our own cells which have become infected (eg through virus)
what are regulatory T cells
regulate or suppress other cells in the immune system
what do B cells produce
antibodies
what does clonal expansion of B cells lead to
plasma cells
memory B cells
what encompasses innate immunity
first line of defence from 1-4 days
no memory immunity
response are braod spectrum and non-specific
name three innate immune mechanisms
physical barriers
cellular mechanisms
plasma factors
how is the epithelium involved in innate immunity
barriers as a lining / structural / mechanical support
they can produce different compounds to fight infection
how do antimicrobial peptides kill microbes
by disrupting the membrane
name three ways in which secretory IgA kills microbes
binds to flagella and prevents motility
binds and neutralises bacterial toxins
prevents attachment of bacteria to mucosal surfaces
how does lysozyme kill microbes
targets the cell wall of bacteria
present in saliva
what are the main receptors on immune cells
toll like receptors
what receptors are used for fungal recognition
dectin and glucan receptors
what receptors are used for allergen recognition
protease-activated receptors
what are cytokines
signalling molecules to co-ordinate immune responses
what are the three types of cytokines
autocrine - alter behaviour of the cell they were secreted from
paracrine - alters neighbours
endocrine - enters circulation
what are pattern recognition receptors (PRRs)
receptors that recognise unique features of microbes
what is the main immune cell type in the oral cavity
neutrophils
how are neutrophils recruited
they are attracted along a CXCL8 (IL-8) gradient to the site of inflammation
what are the four outcomes when there is microbial recognition by innate immune cells
phagocytosis
degranulation
antigen presentation
mediator release
what are the main mediators released by innate immune cells
cytokines and chemokines
what occurs in degranulation
the granules - which are vesicles containing preformed mediators are released
name three types of granules
proteinases
antimicrobials (AMPs)
chemical mediators (histamine)
name three main roles of histamine
vasodilation
increase vascular permeability of blood vessels
smooth muscle contraction
what are the seven stages in phagocytosis
recognition
engulfment
phagosome
phagolysosome
cell digestion
residual bodies
exocytosis
what is MHC1 involved in
presentation of endogenous proteins
what is MHC2 involved in
presentation of expgneous proteins
what is complement
collection of soluble proteins present in circulation
produced by liver
leads to formation of membrane attack complex
what is diapedesis
the process by which neurophils
what are anaphylatoxins
fragments of complement proteins
