6.3 Flashcards
leucocytes
white blood cells
granulocyte - contain granules
-neutrophil
-eosinophil
-basophil
agranulocyte - no granules
-lymphocyte
-monocyte
non specific response
physical, chemical and mechanical barriers
attempt to stop all pathogens
biological responses
examples of non specific immune response
skin
tears-lysozyme
stomach acid
washing- sneezing, weeing
inflammation
inflamation
second defence
lucocytes drawn to infected area
- fight and eliminate
-tissue repair
mast cells degranulate forming histamines
histamines then move the leucocytes by causing the capillaries to dilate
increase in cells so inflamed
temprerature increase
hypothalamus increases temp to inhibit bacteria growth
prolonged high temperatures can damage tissues and cause water loss
mast cells
reside in skin and mucosal tissue
activate when come into contact with foreign antigens
release histamines when activated
phagocyte
detect foreign antigens
engulf pathogen by phagocytosis to form phagosome
Lysosomes release enzymes into the phagosome that hydrolyse proteins & lipids to digest & destroy the pathogen.
basophils
release histamines
circulate in bloodstream
eosinophils
lobed nucleus allowing to engulf pathogens
produce chemicals that counter inflammation
humoral response
body fluid
specific antibodies
cell mediated response
response to own body cells that have altered self antigen
e.g cancer / virus
mhc
Major Histocompatibility Complex. It is a molecule found on the cell surface membrane of all cells and is used to present antigens, both self and non-self.
antigen presenting cell
Phagocytes (neutrophils and macrophages)
phagosome
lysosome
Cytokines
once they engulf they will present part of the cell on their surface attached to mhc
phagocytosis
Phagocytic cells such as macrophages, engulf and digest pathogens.
They then present antigens of these pathogens on their surface.
Antigens are presented to T cells and their T cell receptors, this then activates those cells.
Activated T cells divide by mitosis, creating many more identical copies of each specific cell T cell.
helper t cells
T Cells are made in the bone marrow, but mature in the thymus gland
Each helper T Cell has a unique T Cell receptor on its surface that fits a specific antigen.
T cells can only recognise antigen presented to them on MHC from an antigen presenting cell
Activated T Cells divide rapidly by mitosis, creating many clones.
These Helper T Cells will activate other cells in the cell-mediated response.
-Develop memory cells
-Stimulate phagocytes
-Stimulate B-cells
some remain as memory cells
t helper cell activation
bacteria engulfed and digested
antigen attached to mhc antigen
macrophage becomes antigen presenting cell to t helper
cd4 of t helper cells bind to macrophage
killer t cells (Cytotoxic)
Killer T-cells can attack body cells which have been antigenically altered by viruses or cancer cells.
They destroy the pathogen by punching holes through their cell surface membranes so the cell contents spill out. This is called cell lysis.
B cells
made and matured in the bone marrow
Mature B cells circulate in the bloodstream concentrated in the lymph glands, where lymph fluid drains back into the blood.
each produce a specific antibody (protein) that target specific pathogens/antigens
produce antibodies
can be attached to membrane or released
recognise antigens
clonal selection
selecting the right close of b and t cells
- complimentary
activation of specific b cell with complimentary
clonal expansion
cell undergoes mitosis so more cells have correct antibodies ( proliferation)
differentiation
b cells -
- plasma cells
-b memory cells
t cell independent
without t cells
A B cell and its membrane-bound antibodies recognises and attaches to antigens (free or attached to pathogens).
The B cell becomes activated, divides by mitosis and produces antibodies.
t cell dependant
- A B cell antibody receptor matches with its complementary antigen. A B cell internalises the antigen and presents it on its surface, a bit like an antigen presenting cell.
- An activated T cell (by the same pathogen) binds to the B cell, via this presented antigen..
- The T cell produces cytokines which activate the B cell.
After activation, the B cell divides by mitosis to produce memory B cells and B effectors cells.
B effector cells eventually differentiate into antibody producing plasma cells.
Antibody opsonisation
a process by which a pathogen is marked for phagocytosis.
neutralisation
antibodies bind to and inactivate viruses and toxins
agglutination
antibodies attach to complimentary antigens and binding them together to form multiple pathogens together in a clump this prevents them moving through the body
humoral response extended
virus has antigens on surface that bind to complimentory B cell receptors
B cellls become antigen presenting cells
complimentary t helper cells bind to b cells and produce cytokines
which activate b cells
b cells differentiate into plasma cells
which secrete antibodies
time delay between infection and symtoms
time needed for
-enough cells to be damaged to cause symptoms
-to attach to host cells
-to infect host cells with virus
-new proteins
-assembly of new viruses
exotoxins
-ve and +ve
protiens
living bacteria
endotoxins
-ve only
lipopolydsaccharides
released from dead bacteria
later affect
penicilin
bacteriocidal
-kills bacteria
tetracycline
bacteriostatic
cells with rna virus
rna made
capsid made
assembly of new viruses
antibody producing cell
plasma cell
irridation of cells + mitomycin
stops dna replication
so only one cells uptake measured
primary immune response
antibody producing cells
apc binds to cd4
t memory cells activated
release cytocines
b memory cells activated
plasma cells release antibodies
