Related Experiment Video
Updated: Jul 27, 2026

A Rapid Automated Protocol for Muscle Fiber Population Analysis in Rat Muscle Cross Sections Using Myosin Heavy Chain Immunohistochemistry
Published on: March 28, 2017
[Ultrastructural changes in skeletal muscle in polymyalgia rheumatica]
Abstract:
Skeletal muscle from 21 patients with clinical confirmed polymyalgia rheumatica (PMR) were examined electronmicroscopically. The changes were classified according to 15 ultrastructure criteria. The focal changes have a regressive character and, while they are nonspecific, the systematic assessment of all criteria produced a characteristic pattern in which the ultrastructural picture of skeletal muscles provided a certain profile in cases of PMR. The functionally most important ultrastructural change concerns the mitochondria. Deposition and deformation of crystals result in mitochondrial changes which are structurally definable and are harmful to cell respiration. They are compensated by new formation and accumulation of mitochondria. Comparative analysis of regressive skeletal changes and of processes in the region of the media of the muscular arteries demonstrates analogous morphological changes which point to a common harmful and overlying systemic process in PMR and giant cell arteritis. Changes in the ultrastructure of the kind and degree described cannot be explained by inflammatory or noninflammatory arterial occlusions.
Related Concept Videos
Microscopic Anatomy of Skeletal Muscles
The muscle sarcolemma is a plasma membrane enclosing each muscle cell that conducts electrical signals called action potentials. The sarcolemma extends into the cell to form T-tubules, ensuring the neural impulses are uniformly distributed across the entire muscle...
Disorders of the Skeletal Muscle
Musculoskeletal disorders
Musculoskeletal disorders involve injuries and conditions affecting the skeletal muscles and associated connective tissues. These disorders can arise from acute biomechanical stresses or chronic overuse and can occur across different age groups. Common injuries include sprains, fractures, and muscular strains, often resulting from...
Rheumatic Heart Disease I: Introduction
Myasthenia Gravis ll: Pathophysiology
Alterations in Muscle Tone ll
Alterations in Muscle Tone lll

