Sliding Filament Theory

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   In my life I'm constantly busy doing different things especially at this time of year. From  going to school, then cross country, going home quickly eating, come back to school and going to band. Then to go to home eat and then finally crack down on homework. From all this walking and running around we don't think much of it , other than your muscles felling soar at the end of the day, but really there's more to a muscle then what I thought. For example we'll use the calf muscle ( gastrocnemius).     This muscle is connected to the bone by a tendon which is connected to the epimysium. It then breaks down to the fascicles and finally to the muscle fiber ( cell) inside of the muscle fibers of the myofibril, inside of that is the those and thin filements. The thin filament is called actin and the thick filament called myosin. The actin is connected  to the z line.the actin and myosin stick up in between each other, the myosin has two separate actin filaments on the ends of it, this whole little section is called sarcomeres. in the muscle fiber these sections of  sarcomere pair up next to each other so that the connection takes place.     Now to go more in depth. Muscle contractions start when a nerve impulse is initiated. Motor neurons which doesn't make contact with the muscle but leaves a gap In between called a synaptic cleft.  When stimulus reaches the synaptic cleft, a chemical is released. This is called a neurotransmitter,the neurotransmitter used in muscle contractions called, acetylcholine ( Ach). The Ach diffuses across the synaptic cleft and makes contact with the sarcolemma (muscle cell membrane).     When Ach makes contact with the sarcolemma, a contraction wave spreads throughout the muscle cell.A muscle tubes going through it, these tubes are called sarcoplasmic reticulum (SR). The function of the SR is to store and release calcium ions (Ca) into the muscle. This is very crucial to the contraction process. As the wave spreads, the SR becomes...
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