Difference between revisions of "Category:Chronic Inflammation"

From WikiVet English
Jump to navigation Jump to search
(Created page with " ==Types== ===Granulomatous Inflammation=== * Granulomatous inflammation is usually caused by organisms of low virulence but great persistence, or by implanted foreign bodies....")
 
Line 1: Line 1:
 
 
==Types==
 
==Types==
===Granulomatous Inflammation===
+
===[[Granulomatous Inflammation]]===
 
 
*  Granulomatous inflammation is usually caused by organisms of low  virulence but great persistence, or by implanted foreign bodies.
 
* Classically appears as a '''granuloma'''.
 
** NOT a tumour, despite the suffix "-oma".
 
**  A circumscribed sphere of chronic inflammatory cells enveloped by  poorly organised attempts at encapsulation by local connective tissue.
 
* The differences between a granuloma and an abscess must be appreciated.
 
** The fibrous envelope is never as well developed as that of an abscess.
 
**  The inner contents are never as completely fluid as in an abscess.
 
 
 
====Structure of a Granuloma====
 
 
 
=====Central core=====
 
 
 
* The central core which contains the agent.
 
* The agent may be visible with H&E staining in section, e.g.
 
 
 
** ''[[Actinobacillus lignieresii]]''
 
*** The cause of "Wooden tongue" in cattle.
 
*** Appears as a granule, with a central core of the bacterial colony surrounded by radiating eosinophilic "clubs".
 
**** Clubs are considered to be formed from degenerating collagen and antigen-antibody complexes.
 
** ''[[Actinomyces bovis]]''
 
*** The cause of "Lumpy Jaw" in cattle.
 
*** Forms granules containing bacteria and "clubs".
 
** Fungal hyphae
 
** Parasitic larvae
 
** Foreign bodies
 
* The agent might not be visible without being selectively stained.
 
** E.g.  [[:Category:Mycobacterium species|''Mycobacterium tuberculosis'']] and ''[[Brucella abortus]]''.
 
*** Stain using an acid-fast stain (Ziehl-Neelsen), or a modification.
 
*** These organisms are intracellular in the macrophages.
 
 
 
=====Chronic Inflammatory Cells=====
 
 
 
* Outside the core is a substantial number of chronic inflammatory cells.
 
** Mainly macrophages.
 
*** Often appear as epithelioid cells.
 
** Lymphocytes
 
** Plasma cells.
 
*  Neutrophils and necrotic remnants of cells can be quite prominent in  the granulomas of [[:Category:Actinobacillus  species|''Actinobacillus'']] and  [[:Category:Actinomyces|''Actinomyces'']] species.
 
* Eosinophils are prominent in parasitic granulomas.
 
* A scattered and variable number of Giant cells are often seen, but not always in every granuloma.
 
 
 
 
 
=====Outer Envelope=====
 
 
 
* The final layer is an outer envelope of incomplete fibrous tissue.
 
* Giant cells can also be seen in this area.
 
 
 
====Gross Appearance of Granulomas====
 
 
 
* The cut surface of granulomas varies considerably;
 
 
 
** Tuberculous granulomas tend to have solid whitish cores which are often calcified.
 
*** Grate on the knife when cut through.
 
** Parasitic granulomas are often greenish in colour due to the substantial numbers of eosinophils.
 
*** Older ones are also often calcified.
 
**  [[:Category:Actinobacillus species|''Actinobacillus'']] and  [[:Category:Actinomyces|''Actinomyces'']] species often have liquefied  cores due to the necrosis and [[Neutrophils|neutrophils]].
 
*** I.e. they are purulent.
 
*** May discharge to the surface along sinus tracts.
 
*** The central core of bacteria and ‘clubs’ may appear as yellowish granules in this pus.
 
**** Often called "sulphur granules".
 
  
 
===Granulation Tissue===
 
===Granulation Tissue===
Line 76: Line 14:
 
* Ulcers and open wounds may heal by granulation.
 
* Ulcers and open wounds may heal by granulation.
  
 +
[[Category:Chronic Inflammation]][[Category:To Do - Blood]]
 
===Lymphocytic Inflammation===
 
===Lymphocytic Inflammation===
  
Line 93: Line 32:
 
*#** Ee.g. [[:Category:Mycoplasmas|Mycoplasmosis]] in swine and calves.
 
*#** Ee.g. [[:Category:Mycoplasmas|Mycoplasmosis]] in swine and calves.
  
 +
[[Category:Chronic Inflammation]][[Category:To Do - Blood]]
 
[[Category:Inflammation]]
 
[[Category:Inflammation]]

Revision as of 11:28, 4 August 2010

Types

Granulomatous Inflammation

Granulation Tissue

Granulation tissue (Courtesty of BioMed Archive)
  • Is completlely different to granulomatous inflammation, despite the similarity in name!
  • Occurs on the surface of the skin where large areas of the epithelium have been lost.
  • Makes up the lining of sinus tracts discharging from deeper lesions.
  • Takes its name from the gross appearance of the small vessels which appear at the surface.
    • Look like red granules.
    • These vessels supply inflammatory cells, mainly neutrophils, to the infected surface.
  • The most frequent example in domestic animals is the formation of excessive granulation tissue on the legs of horses with poorly healing wounds.
    • "Proud flesh"
  • Ulcers and open wounds may heal by granulation.

Lymphocytic Inflammation

  • Lymphocytic inflammation is a diffuse chronic ongoing inflammation.
  • Seen in:
    1. Diseases of the central nervous system.
      • Lymphocytes appear microscopically as several layers of cells around blood vessels in the perivascular space.
      • They indicate that there is damage to the nervous tissue further in.
        • Should alert to the possibility of viral infection, which is a common cause of central nervous system disease.
          • E.g. louping ill.
    2. The gut.
      • An excessive number of lymphocytes diffusely infiltrating the lamina propria, often in conjunction with plasma cells, indicate an ongoing non-specific chronic enteritis.
    3. The respiratory tract.
      • Peribronchial and peribronchiolar cuffing may occur to the point of actual lymphoid follicle formation in these areas.
        • Follicles are sometimes large enough to cause partial occlusion of the airways.
      • A feature of some chronic lung diseases.

Pages in category "Chronic Inflammation"

The following 4 pages are in this category, out of 4 total.