Topic 3 â skeletal muscle Lecture 1 skeletal muscle anatomy I ... - AWS
Topic 3 – skeletal muscle Lecture 1 skeletal muscle anatomy I=inhibitory effect à inhibits contractions à relaxed muscles C = Ca binding T= Tropomyosin binding component • Titin = connects M line to the Z line so everything stays in place and responsible for muscle elasticity • Nebulin plays important role in regulation of thin filament length and connection of adjacent myofibrils. o Nebulin winds around actin filaments and gives structural support. o Nebulin also caps the protein at a certain length o Adds strength and stops depolarization of actin • I band = actin only • A band = myosin
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summation occurs because the Ca does remain elevated long enough during a single action potential for substantial binding of Ca to troponin c
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Ca = trigger for muscle contraction à removes inhibition All troponin being bound = max force Small motor units are ususally recruited first In some muscles (usually small muscles) motor neuron firing frequency may also be used to increase force in a graded manner
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summation occurs because the Ca does remain elevated long enough during a single action potential for substantial binding of Ca to troponin c
• • • •
Ca = trigger for muscle contraction à removes inhibition All troponin being bound = max force Small motor units are ususally recruited first In some muscles (usually small muscles) motor neuron firing frequency may also be used to increase force in a graded manner
