Difference between revisions of "Exudation of fluid"
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** Alternatively, they may progress to a more serious reaction. | ** Alternatively, they may progress to a more serious reaction. | ||
* Fibrinous exudates may also resolve if the fibrin is digested by macrophages. | * Fibrinous exudates may also resolve if the fibrin is digested by macrophages. | ||
− | ** In the pleural and peritoneal cavities, the fibrin may become | + | ** In the pleural and peritoneal cavities, the fibrin may become organised into fibrous tissue, producing adhesions between the visceral surface. |
* Diphtheritic inflammation will only repair by scar formation. | * Diphtheritic inflammation will only repair by scar formation. | ||
* If haemorrhagic lesions are widespread, they most commonly associated with acute deaths. | * If haemorrhagic lesions are widespread, they most commonly associated with acute deaths. |
Latest revision as of 16:57, 29 December 2014
Functions of Exudate
- Dilutes the toxic agent, reducing its effect upon the tissue cells.
- The protein components may contain antibodies which attack or coat (opsonise) the irritant.
- This makes the irritant more digestible to neutrophils and macrophages.
- Exudates may contain fibrin.
- This is very sticky - immobilises the irritant.
- Provides a framework over which the leukocytes crawl to reach the irritant.
- Fibrin is also chemotactic to neutrophils, bringing more of these cells into the injured area.
- Exudate on a suface will wash away the irritant.
- E.g the skin and alimentary track.
- Brings the irritant to the lymph nodes, via the lymphatics, for further processing or antigen presentation.
- Preferably within white blood cells such as macrophages and neutrophils.
- Local lymph nodes may also be inflamed following inflammation of a tissue which drains into them.
Sequelae to Exudation
- Catarrhal and serous exudationresolve when the irritant is overcome.
- Alternatively, they may progress to a more serious reaction.
- Fibrinous exudates may also resolve if the fibrin is digested by macrophages.
- In the pleural and peritoneal cavities, the fibrin may become organised into fibrous tissue, producing adhesions between the visceral surface.
- Diphtheritic inflammation will only repair by scar formation.
- If haemorrhagic lesions are widespread, they most commonly associated with acute deaths.
- For example in acute viral, bacterial or toxic diseases.
- If the exudation is strictly localised, for example in brusing, then repair may occur.
- The resolution of abscesses depends upon their location.
- If the abscess is near to a surface it will rupture onto it.
- This is beneficial in the skin where it discharges to the exterior, hopefully getting rid of the pyogenic organism.
- If the abscess is in deeper tissues, there is extensive fibrous capsule formation.
- The fluid becomes inspissated due to withdrawal of water content.
- Macrophages digest the necrotic remains.
- Fibrous tissue organises the interior.
- The very end result is a fibrous scar.