PHYSIOLOGY OF SKELETAL MUSCLE

Skeletni mišići djelatni su organi lokomotornog sustava. Oni su pod kontrolom naše volje. Obično se skeletni mišići opisuju kao poprečno-prugasti, zbog pruga u njihovoj strukturi vidljivih pod mikroskopom, koja je posljedica rasporeda kontraktilnih elemenata unutar mišićne stanice. Pokretanje skeletnog mišića uvijek kreće s živčanim impulsom, koji se prenosi u obliku akcijskog potencijala motoričkim neuronima, koji zatim inerviraju mišićna vlakna. Interakcijom aktina i miozina, dvaju proteinskih filamenata dolazi do kontrakcije. Energija potrebna za ostvarivanje kontrakcija akumulirana je u stanicama I proizvodi se tijekom mišićnog rada aerobnim I anaerobnim procesima. Ovaj rad opisuje strukturu skeletnih mišića, te objašnjava mehanizme kontrakcije. Također su opisani načini namicanja energije u mišićnom radu, te zamor mišića.The skeletal muscles are the effector organs of the locomotor system. They are under voluntary control. Skeletal muscle is described usually as striated muscle because of its striped microscopic appearance, which results from the ordered and regular arrangement of the sub-cellular contractile elements. The stimulus for physiological skeletal muscle activity is always derived from a nerve impulse,and transported in the form of action potential, through the nervous system to the motor neuron that innervates the muscle fiber. Muscle contraction results from the interaction of actin and myosin, two filamentous proteins in the muscle cell. Energy for contraction is accumulated in the cell, and produced by aerobic and anaerobic processes during muscle contractions. This paper describes structure of skeletal muscle, and explains mechanisms of skeletal muscle contraction. It is dealing also with energy production, and muscle fatigue as well