Module 4 - Topic 3-4: The immune system, Inflammation and Repair Flashcards
Inflammation
response of the body to tissue damage
maintains homeostasis
How inflammation maintains homeostasis
removing injuring agent
preventing spread
repairing the barrier
Basic symptoms of inflammation
redness swelling heat pain impaired tissue function
Inflammation important events
changes in diameter and permeability of blood vessels
emigration of white blood cells into surrounding tissues
Production and release of chemical substances
diapedesis
migration of white blood cells into surrounding tissues
Acute inflammation
fairly minor
rapid onset but last a few days at max
primary response of acute inflammation
release of inflammatory mediators
inflammatory mediators - function
alter the diameter and permeability of blood vessels
histamine - location
mast cells inside dermis
Histamine - function
binds to specific receptors causing blood vessels to dilate, leading to redness of area
produces hives in allergic reactions
erythema
redness and heat of area due to vasodilation
Mast cells and basophils - function in inflammatory response
release potent mediators that act on infected cells
contain cystoplasmic granules
Mast cells - location
connective and dermal tissues
dont circulate in blood stream
Basophils - location
from bone marrow
released into blood circulation
may settle into tissues if stimulated
cytoplasmic granules
store mediators of inflammation
degranulation
extracellular release of mediators
factors that induce degranulation
physical destruction - high temp
chemical substances - toxins and poisons
endogenous mediators - tissue proteases
immune mechanisms - IgE independent and dependent
IgE independent
anafylatoxins (C5a,C3a,C4a) are formed during activation of complement system
degranulation is triggered through C5a receptors on surface of mast cells and basophils
IgE dependent
elicited by aggregation of immunoglobin E (IgE) bound to high affinity receptors on surface of mast cells and basophils
Chemotactic factors
released from sites of inflammation and stimulate amoeboid migration of leukocytes out of blood stream
chemotaxis
chemical attraction to a site of injury
protective leukocytes
die after destroying invading agents
pus
presence of a large number of neutrophils
leukocytosis
promotes production and release of leukocytes
fibroblasts - inflammatory response
once debris and bacteria has been removed, fibroblasts synthesize new tissue components
Fever
caused by pyrogens secreted by leukocytes exposed to bacteria in the body
Chronic inflammation
if agents arent removed, tissue will proceed to chronic state, which persists for several weeks, months or years
starts as acute response but proceeds further
Chronic inflammation - noticeable feature
replacement of neutrophils by large number of lymphocytes and monocytes
lymphocytes and monocytes - function
second line of defense
bring with them additional defense power
Immune system
specific defence system
systemic
has memory
Agents - makeup
are tailor made so only attack specific target
how agents recognise target
the body must receive prior exposure to the agent before it can build a proper defence
Antigens
provoke immune response
foreign to body
usually proteins
outer surface of bacteria and virsus
antigenic, contain a variety of foreign proteins
antigenic determinants
certain parts of antigen are immunogenic
immune system activation
releases either free antibodies to bind to antigenic determinants, destroying and neutralising foreign agent
primary response to antigens
produce protective antibodies
antibodies - production
produced by activated B lymphocytes
Antibody binding
bind specifically to respective antigens to form larger structures called immune complexes
Immune complex functions
neutralises toxic antigens
activate formation of inflammatory mediators
immune complexes on surface of bacteria activate complements
target structures for phagocytosis
complements
plasma proteins that drill holes into bacteria cell membrane and cause bacteria to burst
White blood cells - role in immune system
programming, activating and regualtion
Humoral immunity
antibody mediated immunity
B lymphocytes
Cellular immunity
cell mediated immunity
t lymphocytes
B lymphocytes
produce antibodies
b cells
Naiive b cells
has not been previously exposed to antigen, in lymphoid tissues
naive b cell - role
produces unique antibody
how antigens are produces
binding of antigen to correct b cell activates mitosis which produces large number of antibodies
plasma cells
specialised b celles that release large amounts of sntibody
memory cells
b lymphocytes as they remember the antigen and ready to respond to attack at any point
T lymphocytes
display proteins on surface that behave like antibodies
arent secreted and only bind to antigens of surface of abnormal cells
Antigen presenting cells
APC
specialised phagocytic leukocytes which digest antigens and present fragments of antigens on surface
Abnormal cells
cancerous cells
Helper T cells
react with APC
Cytotoxic T cells
react with abnormal cells
Activated helper T cells
stimulate activity of other lymphocytes by synthesising regulatory compounds called cytokine
Helper T cell - TH1
participate in cell mediated immunity
control intracellular pathogens
Helper T cell - TH2
provide help for B cells
essential for antibody mediated immunity
needed to control extracellular pathogens
Activated Cytotoxic cells
physcially attack cell membrane causing abnormal cells to die
Autoimmune disease
when the immune system loses the ability to recognise between foreign and self particles
Multiple sclerosis
attacks myelin on axons of nerves in brain and spinal cord
Diabetes Mellitus (type 1)
attacks the pancreas
Rheumatoid Arthritis
attacks cartilage of bone joints
Systemic lupus erythematosus
attacks the whole body and gives red wolf bite like rash
complement cells
punch holes in cell membrane
Antibody classes
IgG IgM IgA IgE IgD
IgG
most abundant
IgM
first type released in primary response
5 sided polymer
IgA
in bodily secretions
2 polymer
IgE
causes histamine response
increases allergy
IgD
activates B cells
Cellular immunity
made during childhood
Humoral immunity - Active -Naturally acquired
active
infection, contact with pathogen
Humoral immunity - Active - Artificially Acquired
vaccine
dead pathogen
Humoral immunity - Passive - Naturally Acquired
antibodies pass from mother to foetus
Humoral Immunity - Passive - Artifically Acquired
injection of erogenous antibodies
