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| − | ==Mucoid Degeneration== | + | ==[[Mucoid Degeneration]]== |
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| − | * Mucoid degeneration is also known as mucinous or myomatous degeneration.
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| − | * Mucoid degeneration involves changes in epithelial tissue or the extracellular matrix/ ground substance.
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| − | * An extracellular phenomenon of some specific cells.
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| − | ** Tend to show a bluish tinge in H&E stained sections.
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| − | ===Epithelium===
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| − | * The specific cells involved in mucoid degeneration in the eptihelium are:
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| − | ** The goblet cells of wet mucous membranes.
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| − | ** The mucous glands themselves.
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| − | * This is not really a degeneration, but an increased production of mucin.
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| − | ** It is a beneficial reaction; the product
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| − | *** Is important as a lubricant.
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| − | *** Soothes inflamed surfaces.
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| − | *** Traps and dilutes harmful agents.
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| − | *** Carries specific antibodies against infectious agents.
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| − | *** Provides a means for removal of infectious agents.
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| − | ===Connective tissue===
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| − | * Here, the mucin forms part of the ground substance between the fibroblasts that produce it.
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| − | * A disturbance in the metabolism of the fibroblasts under some circumstances,means the ground substance takes on a bluish hue in H&E sections.
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| − | * Mucoid degeneration in the heart valves of middle-aged and older dogs is a common example.
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| − | ** Causes '''endocardiosis'''.
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| − | *** A condition specific to the dog.
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| − | ===Endocardiosis===
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| − | * Tends to affects middle-aged and older dogs.
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| − | * Primarily occurs in the mitral valve.
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| − | * Results in slowly developing heart failure
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| − | * The valves become swollen and misshapen
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| − | ** The heart cannot pump blood effectively to the circulation from the left ventricle.
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| − | *** Blood passes back into the left atrium, compromising the filling from the pulmonary vein.
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| − | **** Leads to back pressure on the pulmonary capillaries.
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| − | ***** [[Oedema|Oedema]] forms in the lungs, and can be heard as moist sounds on auscultation.
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| − | ***** Reduces the oxygenation of blood leading to exercise intolerance.
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| − | *** Failure of the left side eventually compromises the function of the right side.
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| − | **** There is pooling of blood in the venous system i.e. in the [[Liver - Anatomy & Physiology|liver]].
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| − | [[Category:Degenerations and Infiltrations]]
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