This is necessary since smooth muscle fibres may be difficult to differentiate from collagen.

Smooth muscle fibres keep it close to the glans but make it highly elastic.

Nudans have only smooth muscle fibres.

This showed loss of smooth muscle fibres, with remaining fibres showing hypertrophy, vacuolation, or degenerative features (Fig 2).

Smooth muscle fibres had a range of ultrastructural abnormalities including myofilament disarray, electron lucency of the cytoplasm, and proliferation of the endoplasmic reticulum.

The dartos muscle is firmly attached to the skin and consists largely of smooth muscle fibres that contract under the influence of cold, exercise, and sexual stimulation.

At light microscopy smooth muscle layers show fibrosis with vacuolar and other degenerative changes in smooth muscle fibres in the circular and longitudinal muscle layers.

It seems likely that the fibrosis typical of this disorder has its origin in the transformation of smooth muscle fibres from a purely contractile to a myofibroblast collagen synthetic phenotype.

In three of these patients (patients 5, 6, and 7), ultrastructural examination, however, showed abnormalities of smooth muscle fibres whilst normal argyrophilic neurones were seen in the silver preparations.

Once there is an influx of calcium cations (Ca) into the muscle, either from the sarcoplasmic reticulum or from the extracellular space, contraction of smooth muscle fibres may begin.

Ultrastructural abnormalities in smooth muscle fibres have been recognised, including myocyte damage with perinuclear vacuolation, disorientation and dissolution of myofilaments, electron lucency of the cytoplasm, and swelling of mitochondria.

Each arrector pili is composed of a bundle of smooth muscle fibres which attach to several follicles (a follicular unit), and is innervated by the sympathetic branch of the autonomic nervous system.

We report detailed ultrastructural studies on tissue from a patient with visceral myopathy in whom there were prominent alterations in smooth muscle fibres of the muscularis propria, which included the presence of cells with the typical appearance of myofibroblasts.

Ultrastructural studies showed increased collagen in the muscularis propria with alterations in smooth muscle fibres including elongation, cytoplasmic vasuolation, proliferation of rough endoplasmic reticulum, myofilament disarray with increased lucency of myocyte cytoplasm, and prominent focal densities.