MUSCLE NERVE CARTILAGE BONE
SKELETAL MUSCLE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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hold muscle cells together.
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are found in the sarcolemma.
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contain myosin and actin myofilaments.
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extend from the sarcolemma to the T-tubule.
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Detailed explanation-1: -Muscles are composed of myofibrils containing the myofilaments actin and myosin.
Detailed explanation-2: -The actin to myosin filament ratio varies from 3 to 4 within each individual myofibril. The described variability of the actin filaments arrays leads to several difficulties in an explanation of the mechanism of muscular contraction.
Detailed explanation-3: -Skeletal and cardiac muscles are known as striated muscles, because the filaments of actin and myosin that power their contraction are organized into repeating arrays, called sarcomeres, that have a striated microscopic appearance.
Detailed explanation-4: -Myofibrils constitute the contractile system, which consists of four complex proteins: myosin, actin, tropomyosin, and troponin. These four proteins are arranged into a functional unit called a sarcomere (see Fig.