Acute Inflammation Flashcards
Name the causes of acute inflammation
Microbial infections, hypersensitivity reactions, physical and chemical agents
What are the symptoms of acute inflammation?
Red (rubar) - dilation of blood vessels
Hot (calor) - Peripheral increase in temperature due to increased blood flow (hyeraemia)
Swollen (tumor) - Due to Oedema
Painful/tender (dolor) - due to stimulation of nerve endings by pressure and chemical mediators
Loss of function.
Name the two phases of acute inflammation
Vascular phase - dilation and increased permeability
Exudative phase - fluid and cells escape from permeable membranes.
Describe the feature of exudate
High protein content, some of these may be immunoglobins which are important for the destruction of invading organisms. Fibrinogen is converted to fibrin which will cover acutely inflamed organ surfaces. There is a high turnover/drainage as exudate is continuously removed by the lymphatic system.
What is fibrinogen?
A glycoprotein that circulates the blood, during tissue or vascular damage it is converted to fibrin by enzymes.
Describe the differences between exudate and transudate
Exudate; Net flow of plasma and fluid out of vessels because of increased vascular permeability. There is a high protein content.
Transudate; NO net flow out because of normal vascular permeability. There is a low protein content.
What causes increased vascular permeability?
Chemical mediators such as histamine. It stimulates the endothelium cytoskeleton, directly changing but not damaging the endothelium. This is confined to post capillary venules.
Describe occurs with the lymphatic system in actue inflammation
Lymphatic vessels dilate as they drain fluid from exudate. Antigens are carried to lymph nodes which are recognised by lymphocytes triggering an immune response.
What is lymphangitis?
Inflammation of a lymphatic vessel
What is lymphadenitis
Inflammation of a lymph node
What is the cellular component of acute inflammation?
Neutrophils which accumulate in extracellular space, this is diagnostic feature of acute inflammation
Describe some of the features of Neutrophils
They kill organisms, degrade necrotic tissues, ingest offending agents, produce chemical mediators, toxic oxygen radicals and tissue damaging enzymes.
What is margination?
The process of white blood cells adhering to the walls of a blood vessel (the endothelium).
What is pavementing?
The flattening of white blood cells
Define chemotaxis
The movement of a cell or organism in response to a gradient of a particular substance.
Name some chemotactic compounds
Bacterial products, complement components and products of neutrophil activity.
Name the four plasma enzymatic cascade systems
Complement system, the kinins, the coagulation factors and the fibrinolytic system.
What are opsonins?
A molecule that enhances phagocytosis means that it can be undergone much more efficiently. They bind to specific receptors on leucocytes.
Name some major opsonins
The Fc fragment of IgG. C3b which is a fragment of C3 and collectins - a plasma protein that binds to microbial cell walls.
What is suppuration?
The formation of pus
What is pus made out of?
Neutrophils, bacteria and cellular debris.
Name some acute inflammatory responses and how they present
Serous - protein rich fluid exudate
Catarrhal - mucus hypersecretion
Fibrinous - exudate contains plentiful fibrin
Haemorrhagic - severe vascular injury
Suppurative - production of pus
Membranous - epithelium coated by fibrin
Psudomembranous - superficial mucosal slough
What occurs when an abscess is drained?
The cavity collapses and is destroyed by organisation and fibrosis
What is fibrosis?
Formation of excess fibrous connective tissue which forms in an organ or tissue for repairs
Where do deep seated abscesses drain?
Along sinuses or fistulas.
what is bronchopneumonia?
A type of pneumonia which causes inflammation of the lungs
What is an ulcer?
A local defect or excavation of the surface of an organ or tissue that is produced by the removal of inflammatory tissue.
Where are ulcers most commonly encountered?
When there is inflammatory necrosis of the mucosa (mouth, stomach or intestines)
and chronic leg ulceration in patients with circulatory issues
Name and describe some of the beneficial effects of acute inflammation
Dilution of toxins which allows them to be carried away by lymphatics, Entry of antibodies due to vascular permeability, Fibrin formation which prevents the movement of microorganisms, Transportation of drugs because of increased vascular permeability, Delivery of nutrients & oxygen aided by increased fluid flow, Stimulation of immune response as fluid exudate containing antigens reach lymph nodes.
Describe the harmful effects of acute inflammation
Digestion of normal tissue, Swelling (laryngeal oedema and brain swelling, and inappropriate inflammatory responses (allergic reactions)
Describe some of the systemic effects of acute inflammation
Pyrexia - rise in body temp even by a few degrees can improve efficiency of leukocytes and impairs the replication of offending micro-organisms.
It can also cause constitutional syptoms such as malaise, anorexia and nausea. The weight loss is due to negative nitrogen balance, common with chronic. Reactive hyperplasia of the reticuloendothelium system. Haematological changes and increased erythrocyte sedimentation rate.
