Processos adaptativos do tecido muscular esqueletico e tecido conjuntivo : repercussões sobre a flexibilidade

AUTOR(ES)
DATA DE PUBLICAÇÃO

1997

RESUMO

This study has as its objective to discuss the control mechanisms of structural adaptations in the connective and muscular tissues under different functional conditions. It consists in the development of the interpretations about the plasticity of the tissues related to physical activities in order to improve the motor system s flexibility. Therefore, this bibliographic research, based on the identification, localization and compilation of the data seeks the utilization and ordenation of available knowledge pertinent to studying the object. It makes use of analysis and interpretative techniques and deduction to construct and develop the relationship between the observations and considerations of the authors. Connective tissues has a significant role in the process of stretching adaptation. The most important data is that the adaptation relative to increasing the functional activity increases collagen synthesis, stimulates the glycosaminoglycan production and increases the cross-seccional area, the number of fibroblast nucleuses, the diameter of collagen bundles and resistance toward tendon traction. This tissue reacts structurally to the privation movement that decreases the protein synthesis and the glycosaminoglycan production, which are associated with decreased water, increase the crystals in collagen bundles increasing the cross-link number. On the other hand, the decrease of elasticity occurs and the tendon s elastic stiffness increases and the tissue becomes subject to fragmentation. Muscular tissue presents great adaptive capacity, being the main place for morphological changeswith reflection on the flexibility capacity of the osteomyo-tendinous. The muscle is able to adapt itself functionally through passive tensions increasing the protein synthesis and consequently, the size of the fiber is increased by the addition of in-series sarcomeres at the extremity of the fiber increasing muscle size and the relaxation of "stress". In the absence or decrease of movement that induces hypokinety and hypodynamy, the decrease of protein synthesis occurs as a consequence of the reduction muscular tension, becouse there is no adequate position between actin filaments and myosin. In this condition, atrophy is observed, decrease of the length and diameter of fiber in consequence of the reduction of in-series sarcomeres. Adaptation results in the remodeling of the intramuscular connective tissue, reduction of maximum contractible strength and of the length/tension curve. This leads to minor extensibility and major tissue stiffness. Muscular stretching, considering. the plastic changes that induce permanent modifications, depending on its intensity, time and frequency, leads to an adaptive process of the tissues in function of a new demandoThis occurs as a consequence of the increaseof the number of in-series sarcomeres, decreasing the tension at the union of muscle-tendon. Consequently, the tissues acquire a new length, a greater relaxation capacity, reduction of stiffness and a consequent increase of flexibility. These data permit deducing that the motor system s flexibility is influenced by the levei of the exercised tension on the tissues, by disposition of the fibers in relation to the tendon, by the degree of extensibility of the collagen fibers of the tendon and skeletal muscular fibers and by articular capsule. Ali these represent the limiting factors of this property

ASSUNTO(S)

plasticidade alongamento (fisiologia) tecido conjuntivo exercicios fisicos

ACESSO AO ARTIGO

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