| Term 
 
        | The four functions of the muscle system |  | Definition 
 
        | 1. Movement 2. Maintenance of posture
 3. Joint stabilization
 4. Heat generation
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        | Term 
 
        | characteristics of skeletal muscle |  | Definition 
 
        | -multinucleate -striated with visible banding
 -voluntary
 -easily fatigued
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        | characteristics of smooth muscle |  | Definition 
 
        | -no striations -single nucleus
 -involuntary
 -tireless
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        | characteristics of cardiac muscle |  | Definition 
 
        | -has striations -joined to another muscle cell at an intercalated disk
 -involuntary
 -found only in heart
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        | Term 
 
        | long cells shorten and generate pulling force |  | Definition 
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        | electrical nerve impulse stimulate the muscle cell to contract |  | Definition 
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        | can be stretched back to its original length by contraction of an opposing force |  | Definition 
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        | can recoil after being stretched |  | Definition 
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        | functional unit of the skeletal muscle |  | Definition 
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        | Term 
 
        | long rows of rpeating segments in a myofibril |  | Definition 
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        | Term 
 
        | the boundaries of each sarcomere |  | Definition 
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        | Term 
 | Definition 
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        | Term 
 
        | extend from z line toward the center of the sarcomere |  | Definition 
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        | Term 
 | Definition 
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        | Term 
 
        | located in the center of the sarcomere |  | Definition 
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        | Term 
 
        | the full length of the thick filament, and it is composed of myosin |  | Definition 
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        | Term 
 
        | at rest, the center part of the sarcomere where no thin filaments occur |  | Definition 
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        | Term 
 
        | in the the center of the h zone, and contains tiny rods that hold thick filaments together |  | Definition 
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        | Term 
 
        | region with only thin filaments, and lies within two adjacent sarcomeres |  | Definition 
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        | Term 
 
        | dense regular connective tissue surrounding entire muscle; just deep to fascia |  | Definition 
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        | Term 
 | Definition 
 
        | fine sheath of connective tissue wrapping each muscle cell |  | 
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        | Term 
 | Definition 
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        | Term 
 | Definition 
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        | Term 
 
        | plasma membrane of muscle cell |  | Definition 
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 | Definition 
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        | organelles that are aligned to give distinct bands and are long rods within the cytoplasm |  | Definition 
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        | Term 
 
        | myosin filaments have heads which are known as extensions or _______ |  | Definition 
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        | Term 
 
        | actin filaments have two functional proteins known as... |  | Definition 
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        | covers cross-bridge binding sites when muscle is not contracting |  | Definition 
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        | has binding sites for calcium ions |  | Definition 
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        | released when muscle is stimulated to contact |  | Definition 
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        | specialized smooth endoplasmic reticulum |  | Definition 
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        | calcium ions difusing through the sarcoplasm trigger... |  | Definition 
 
        | the sliding filament mechanism |  | 
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        | Term 
 
        | deep invagination of the sarcolemma of striated muscle cells |  | Definition 
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        | one neuron in which all muscle cells are stimulated by that neuron |  | Definition 
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        | activation by the neurons causes the myosin heads to attach to binding sites on the thin filament |  | Definition 
 
        | the sliding filament theory of muscle contraction |  | 
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        | terminal end of axon that contains synaptic vesicle |  | Definition 
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 | Definition 
 
        | vesicle that contains a chemical neurotransmitter |  | 
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        | neuro transmitter for skeletal muscle |  | Definition 
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        | rate of stimulation increases untiol relaxation phase is eliminated |  | Definition 
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        | Term 
 
        | prolonged, involuntary, painful muscular contractions |  | Definition 
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        | tears or breaks in a muscle |  | Definition 
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        | wasting away of tissues from lack of use in poor nutrition or ischemia |  | Definition 
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        | the increase in the size of muscle cells |  | Definition 
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        | myofilaments are able to slide past each other during contractions and the muscle shortens |  | Definition 
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        | tension in the muscle increases and the muscle is unable to shorten |  | Definition 
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        | the occurence of muscle fibers contracting in a relaxed muscle |  | Definition 
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        | a high energy molecule in muscles which helps to regenerate ATP |  | Definition 
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