chronic inflammation Flashcards
what is the difference between innate and adaptive immunity?
innate is ready to respond immediately whereas adaptive takes longer and shows memory
what are the characteristics of acute inflammation?
quick onset and offset
what is exudation?
it occurs in acute inflammation when there is increased blood flow into the area and increased fluid leaving through the permeable vessels
what happens in acute inflammation?
releases proteins that are important for the acute immune response such as fibrinogen and cells leak out - usually neutrophils
what are the symptoms acute inflammation?
rubor, calor, dolor, tumor
how can you account for the symptoms of acute inflammation?
exudation - tumor / swelling
increased blood flow - rubor
blood flow - calor
dolor - swelling
what are the outcomes of acute inflammation?
repair or regeneration
repair - organisation occurs through replacement by granulation tissue and a fibrous scar
resolution - phagocytosis of insulting pathogen, fibrinolysis, phagocytosis of debris
what cells are involved in chronic inflammation?
lymphocytes, plasma cells and macrophages - mononuclear inflammatory cells
what happens in resolution?
resolves situation, remove the foreign agent by breaking down, mainly by macrophages
why does repair occur?
it is when there is too much damage for resolution to occur or damage to cells that cannot regenerate
how does repair occur?
organisation - replacement by granulation cells - new blood vessels form and collagen deposition by fibroblasts - collagen causes the scar
why does chronic inflammation occur?
if there is ongoing damage or it isn’t resolved by acute inflammation
what are the issues of the fibrous scar?
it is a defect - can cause issues such as intestine in the abdomen getting caught around the scar
what are the characteristics of innate immunity?
it takes hours to days, there is blood vessel dilation and increased permeability, fluid exudation which is rich in proteins such as Ig, and neutrophil recruitment, mast cells and macrophages
what consists chronic inflammation?
adaptive and innate immunity - two systems exist together
what happens in chronic inflammation?
angiogenesis and fibrosis
what is amyloidosis?
it is when proteins misfold and form aggregates - found in various parts of body and damage the tissues they are deposited in
when does cachexia occur and what is it?
it is weight loss - the patient will be emaciated and it occurs secondarily to cytokine release from CIR
why does anaemia occur?
RBC production decreases and cytokine release affects the way iron is used around the body
what does concomitant mean in chronic inflammation?
two events happen at the same time - tissue destruction and repair
what does H. Pylori cause?
acute inflammation of the stomach, and gastritis
what can cause chronic inflammation?
autoimmunity, unknown, repeated episodes of acute inflammation, progression from acute inflammation, asbestos entering the lungs, toxic agents
what is chronic cholecystitis?
it is repeated inflammation of the gallbladder resulting in chronic inflammation
why does persistent infection result in chronic inflammation?
the infection is hard to remove so the immune system finds it hard to get rid of bacteria
how can we classify toxic agents, and what are examples of each?
exogenous - external stimuli such as asbestos fibres
endogenous - if there is a fragment of bone it is hard to break down and will remain in tissue
why does asbestos cause chronic inflammation?
macrophages cannot break it down so it remains there and fibres cause continual stimuli (same with non-degradable sutures)
why does autoimmunity result in chronic inflammation?
it is a new reaction to self antigens - the antigens are always there so will continue
what is produced in persistent infection that causes chronic inflammation?
reactive oxidative species - attempts to remove the infectious agent will also result in injury
how do H pylori work?
a chronic ulcer is common and destroy all the tissue by perforation
what is another example of chronic infection?
chronic pyelonephritis
what is an example of a condition that occurs due to the prolonged exposure to toxic agents?
cirrhosis - exposure to viruses or alcohol
what is the basis of cirrhosis?
the liver tissue tries to regenerate and forms regenerative nodules, but there is collagen deposition that results in a shrunken liver with poor function
how does asbestos affect gas exchange?
fibres are very small so get into the alveoli of the lung. There is interstitial fibrosis from collagen deposition int the walls of the alveoli
what is deposited in the joint space in RA and what does this result in?
deposition of collagen and immune cells - erosion of underlying bones - deformities in joints
what cells reside in tissues waiting for infection?
mast cells, macrophages and fibroblasts
what is the life cycle of macrophages?
they start in the bone marrow, then migrate into blood as monocytes and then to tissue as macrophages
when are macrophages activated?
they are activated in response to cytokine signals from T cells - ingest foreign agents and phagocytose
what do lymphocytes do?
they emigrate out of the blood vessel to the surrounding tissue. they are mononuclear and go purple on a histology stain
how will plasma cells appear down a microscope?
they will appear with a clockface nucleus with speckles down
what are fibroblasts?
they are long thin cells producing collagen that are responsible for producing scars
what are eosinophils and mast cells used in?
the inflammatory response mediated by IgE which is usually from drugs. they are activated bu IgE
what are the characteristics of eosinophils?
they are for parasitic infections, and are bactericidal - antiparasitic and allergic reactions
how do mast cells appear down a microscope?
they are rarely seen down a microscope - they have a granular cytoplasm and are signalling molecules
how do cells leave the vessels?
they stick to the endothelium of blood vessels as changes to the underling endothelium allow this - follow chemokines to the area of damage
what part does the macrophage play and how does this result in process?
the macrophage is activated in the tissue and produces cytokines and presents to T cells. These then activate and activate B cells which become plasma cells and ABs - inflammatory mediators from T cells further activate macrophages - cycle of chronic inflammation. Macrophages activate fibroblasts and release factors causing angiogenesis
what are B, T and plasma cells?
mononuclear leukocytes
what are multinucleated giant cells?
when macrophages merge together and form giant cell
how will caseating necrosis present?
there will be no outline of cells just a pale pink merge
what is a granuloma and why does it occur?
granulomas are collections of activated epitheliod macrophages - pink cytoplasm, indistinct cell membranes and oval nucleus - occur because the macrophages cannot break down so recruit more and accumulate. This will be surrounded by mononuclear leukocytes
what causes granuloma?
parasitic, fungal, bacterial, unknown, foreign body, or inorganic metals or dust
