topic 3.1 Flashcards
what are the two parts of the immune system?
innate immunity and adaptive immunity
a foreign substance that simulates an immune response and generates antibody production
antigen
a specific protein produced in humoral response to bind with an antigen
antibody
a gland located in superior mediastinum, it is the site of maturations of T lymphocytes
thymus
contain many lmyphocytes, they filter body fluids, remove foreign matter and generate immune responses
lymph nodes
disorders resulting from an overactive immune system that fails to recognise ‘self’
autoimmune disease
specialised lymphocytes produced and matured in bone marrow, they are precursor to plasma and memory cells
B lymphocytes
specialised lymphocytes produced by the bone marrow and matured in the thymus, which is responsible for cell-mediated immunity
T lymphocytes
white blood cells for phagocytosis, an innate defence, they are active in inflammation
neutrophils
white blood cells, they bind IgE and also release histamines
basophils
white blood cells, they participate in allergic responses and defence against parasites
eosinophils
white blood cells, they migrate from the blood into tissues to become macrophages
monocytes
phagocytes, they process and present antigens to lymphocytes for the immune response
macrophages
found within connective tissue, they release chemical mediators such as histamines
mast cells
develop from B lymphocytes to produce and secrete antibodies
plasma cells
they destroy antigens, cancer cells and virus cells
cytotoxic T cells
what is the purpose of cytotoxic T cells?
to destroy antigens, cancer cells and virus cells
remembers antigens and quickly stimulates an immnue response
memory T cells
activates B and T cells, also controls or limits the specific immune response
helper T cells
part of the innate immune system, they destroy foreign cells, virus infected cells and cancer cells
natural killer cells
a generic term for any cell responsible for engulfing pathogens, waste material and foreign bodies
phagocytes
condition of being resistant to infection by a specific pathogen
immunity
a state where the immune system is unable to fight infection
immunodeficiency
agents used to reduce an immune response
immunosuppressants
a type of acquired immunity in which antibodies play the dominant role
humoral immunity
a type of acquired immunity in which T cells play the dominant role
cell-mediated injury
define innate immunity
includes all anatomical structures and processes that:
- prevent entry of damaging substances
- response non-specifically to damaging substance that has entered body
what is the body’s first line of defence?
the skin, mucous membranes, stomach acid, etc.
how does temperature provide a barrier to pathogens?
by inducing a fever, as this inhibits the growth of some pathogens and boost immune function
what are interferons (INF)?
an antiviral substance, helps prevent spread of virus
what is complement?
a cascade of plasma proteins that is effective against bacteria
how does complement work?
- increases inflammation by activating basophils, mast cells + the attraction of neutrophils and macrophages
- eliminates immune complexes
- induces cytolysis by forming MAC transmembrane protein
what is adaptive immunity?
is capable of recognising + selectively eliminating specific dangerous substances
what are the 4 main characteristics of adaptive immunity?
- antigenic specificity
- diversity
- immunologic memory
- self/non-self recognition
what are the 3 types of antigens?
- foreign (come from pathogens)
- tumour (proteins on tumour cells)
- self-antigens (antigens on our own cells)
what are the 5 classes of antibodies?
- IgD
- IgE
- IgM
- IgA
- IgG
what percentage are the 5 classes of antiodies found in the body?
- IgD - 1
- IgE - <1
- IgM - 6
- IgA - 13
- IgG - 70-80
where are the 5 classes of antibodies located?
- IgD - bound to surface of B cells
- IgE - bound to mast cells + basophils
- IgM - involved in early humoral immunity
- IgA- mucous membrane secretions
- IgG - main antibody in humoral immunity
what are the 3 main ways that antibodies work to neutralise/remove damaging substances?
- opsonisation - antibodies coat pathogen, enhance phagocytosis
- complement fixation - antibodies coat pathogen, sigal 4 blood complement system to destroy pathogen
- neutralisation - antibodies coat pathogen, prevents it from replicating + interacting
what does the B cell response most effectively fight against?
pathogens that are extracellular, such as bacteria
explain process of humoral response (B cell response)
- antigen enters body, B cells that recognise antigen get cloned
- these B cells need activation by helper T cells
- activated B cells divide = large population of specific B cell
- most will differentiate into plasma cells, small amount will -> memory B cells to rpovide long-term memory against antigen
what are Th cells?
- helper T cells
- they express surface protein called CD4 so they also called CD4 T cells
what are Tc cells?
- cytotoxic T cells
- they express protein called CD8, so they also referred to as CD8 Tc cells
what is the main role of CD8/Tc cells?
to destroy virus or tumour infected cells
what is the main role of CD4/Th cells?
to activate B cells or Tc cells
what are antigen-presenting cells (APC)?
phagocytes that display phagocytosed pathogens on their membrane
what do antigen presenting cells (APCs) do?
- once displaying the antigen, they move to local lymph node to present antigen to T cells
- this activates the T cells in local lymph node and can cause swelling and tenderness of this node
