14.5 POJA-L6124+6080+6122 Electron micrographs of the junction between skeletal Muscle and Tendon (mouse)
14.5 POJA-L6124+6080+6122 Skeletal Muscle-Tendon linkage
14.5 POJA-L6124+6080+6122 Electron micrographs of the junction between skeletal Muscle and Tendon (mouse)
Title: Electron micrographs of the junction between skeletal Muscle and Tendon (mouse)
Description:
(A, B and C): Finger-like processes of the muscle fibres are spread out and are linked to the fibroblasts and collagen fibrils of the tendon. The plasmalemma there is condensed to subsarcolemmal densities. The tendon fibroblasts fit around the myofibre fingers as fingered glove. The collagen fibrils are anchored in the outer sarcolemma (myotendinal connection or myotendinous junctions). (1): Myofibre. (2): Tendon with collagen fibrils and (3): fibroblast. (T): Triad in (A).
(B): (*) indicates a disintegrating bleb (a swollen cytoplasmic part) with remnants of ribosomes and glycogen. The slender thin extension (red arrows) encompassing the bleb belongs to a telocyte.
(C): Myofibre (1) with part of a nucleus. (4) Telocyte with a slender nucleus. (5) Capillary
Background:
The tapered ends of myofibres are embedded into the ECM (extracellular matrix) of the tendon, forming the myotendinous junction (MTJ). At the interface with the tendon area myofibres develop extensive folding of sarcolemma resulting in an increase in the surface area between myofibres and tendon. This increase in surface area enables the MTJ to withstand the high mechanical stresses generated during muscle contraction. 3D reconstruction reveals that the tendon makes ridge-like protrusions, which interdigitate with groove-like indentations in the muscle cell. The ECM of the tendon contains apart from proteoglycans, elastin, fibronectin mainly collagen type I, and some collagen type III and V. Embryologically tenoblasten give rise to flattened tenocyten with many cellular protrusions. The orientation of tenocytes follows along the direction of the applied force on the MTJ.
Telocytes represent a distinct type of interstitial cells found in the stromal compartment of many organs. These cells show small cellular bodies from which arise very long and thin processes (telopodes) with alternating slender segments (podomers) and small dilated portions (podoms). The telocytes are found near capillaries and satellite cells in the MTJ region where they mediate as active regulator the cross talk with these cells. (Telocytes in skeletal, cardiac and smooth muscle interstitium: morphological and functional aspects Marini M., Rosa I., Ibba-Manneschi L., Manetti M Histol Histopathol 33, 1151-1165, 2018 https://doi.org/10.14670/hh-11-994)
See also
Keywords/Mesh: locomotor system, skeletal muscle, tendon, dense fibrous connective tissue, dense regular connective tissue, collagen fibril, tenocyte, tendinocyte, telocyte, ECM, electron microscopy, POJA collection
Description:
(A, B and C): Finger-like processes of the muscle fibres are spread out and are linked to the fibroblasts and collagen fibrils of the tendon. The plasmalemma there is condensed to subsarcolemmal densities. The tendon fibroblasts fit around the myofibre fingers as fingered glove. The collagen fibrils are anchored in the outer sarcolemma (myotendinal connection or myotendinous junctions). (1): Myofibre. (2): Tendon with collagen fibrils and (3): fibroblast. (T): Triad in (A).
(B): (*) indicates a disintegrating bleb (a swollen cytoplasmic part) with remnants of ribosomes and glycogen. The slender thin extension (red arrows) encompassing the bleb belongs to a telocyte.
(C): Myofibre (1) with part of a nucleus. (4) Telocyte with a slender nucleus. (5) Capillary
Background:
The tapered ends of myofibres are embedded into the ECM (extracellular matrix) of the tendon, forming the myotendinous junction (MTJ). At the interface with the tendon area myofibres develop extensive folding of sarcolemma resulting in an increase in the surface area between myofibres and tendon. This increase in surface area enables the MTJ to withstand the high mechanical stresses generated during muscle contraction. 3D reconstruction reveals that the tendon makes ridge-like protrusions, which interdigitate with groove-like indentations in the muscle cell. The ECM of the tendon contains apart from proteoglycans, elastin, fibronectin mainly collagen type I, and some collagen type III and V. Embryologically tenoblasten give rise to flattened tenocyten with many cellular protrusions. The orientation of tenocytes follows along the direction of the applied force on the MTJ.
Telocytes represent a distinct type of interstitial cells found in the stromal compartment of many organs. These cells show small cellular bodies from which arise very long and thin processes (telopodes) with alternating slender segments (podomers) and small dilated portions (podoms). The telocytes are found near capillaries and satellite cells in the MTJ region where they mediate as active regulator the cross talk with these cells. (Telocytes in skeletal, cardiac and smooth muscle interstitium: morphological and functional aspects Marini M., Rosa I., Ibba-Manneschi L., Manetti M Histol Histopathol 33, 1151-1165, 2018 https://doi.org/10.14670/hh-11-994)
See also
- (14.5 POJA-L6121+6081+6123+6082 Myotendinous junctions in skeletal muscle)
- (14.5 POJA-L6078+6079+6125 Myotendinous junctions in skeletal muscle)
- (14.5 POJA-L6351 Anatomy of transition of muscles into tendon)
Keywords/Mesh: locomotor system, skeletal muscle, tendon, dense fibrous connective tissue, dense regular connective tissue, collagen fibril, tenocyte, tendinocyte, telocyte, ECM, electron microscopy, POJA collection