Changes

* Here, the mucin forms part of the ground substance between the fibroblasts that produce it.

* Here, the mucin forms part of the ground substance between the fibroblasts that produce it.

* A disturbance in the metabolism of the fibroblasts under some circumstances,means the ground substance takes on a

* A disturbance in the metabolism of the fibroblasts under some circumstances,means the ground substance takes on a bluish hue in H&E sections.

bluish hue in H&E sections.

* Mucoid degenration in the heart valves of middle-aged and older dogs is a common example.

* Mucoid degenration in the heart valves of middle-aged and older dogs is a common example.

It occurs primarily in the

mitral valve and is responsible for a

 

condition specific for this species

called endocardiosis.

* Primarily occurs in the mitral valve.

It is important and results in slowly

developing heart failure due to the

** A condition specific to the dog.

inability of a heart with swollen

* Results in slowly developing heart failure

misshapen valves to effectively pump

**The valves are swollen and misshapen, so the heart cannot pump blood effectively to the circulation from the left ventricle. *** A substantial proportion of the blood passes back into the left atrium, compromising the filling from the pulmonary vein. **** Leads to back pressure on the pulmonary capillaries with oedema formation in the lungs.  

blood from the left ventricle out into

the systemic circulation. A substantial

***** Reduces the oxygenation of blood leading to exercise intolerance.

portion of the blood passes back into

**** Failure of the left side eventually compromises the function of the right side.

the left

***** There is pooling of blood in the venous system i.e. in the liver.

atrium and compromises the filling of the atrium from the pulmonary vein. This leads to

back pressure on the pulmonary capillaries with oedema formation in the lungs. This

reduces the oxygenation of blood leading to exercise intolerance and may be heard as moist

sounds on auscultation of the lungs. Eventually, this failure of the left side compromises the

function of the right side and there is also pooling of blood in the venous system i.e. in the liver.

===Hyaline Degeneration===

===Hyaline Degeneration===