Term
| organelles specific to muscle fibers |
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Definition
| multiple nuclei, sarcolemma, myofibrils, microfilaments, sarcomere, zones, bands, & lines |
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Term
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Definition
| plasma membrane of muscle fiber |
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Term
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Definition
| cytoplasm of muscle fiber |
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Term
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Definition
| contain microfilaments; hundreds to thousands of microfilaments per muscle fiber |
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Term
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Definition
| areas of no thick filaments; light space between stripes / striations; MOSTLY contains thin filaments (actin) but not completely |
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Term
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Definition
| area of thick filaments (myosin) where no thin filaments overlap |
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Term
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Definition
| thick filaments (myosin; give muscle fibers their striated appearance |
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Term
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Definition
| between thick filaments; anchor for thin filaments |
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Term
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Definition
| anchor for thick filaments |
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Term
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Definition
| functional unit of skeletal muscle; occurs from Z line to Z line; where action really takes place |
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Term
| excitation-contraction coupling |
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Definition
| stimulus reaches neuron, which sends an electrochemical signal to muscle cell; signal transduces throughout the cell, causing a contraction |
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Term
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Definition
| electrochemical equilibrium (-85mV inside the cell) |
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Term
| ions inside cell membrane of skeletal muscle fibers (sarcolemma) |
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Definition
| low Na, high K, low Ca, low Cl, high Protein |
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Term
| ions outside of sarcolemma |
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Definition
| high Na, low K, high Ca, high Cl, low protein |
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Term
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Definition
| ALL CELLS HAVE PASSIVE CHANNELS/ leaky channels |
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Term
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Definition
| make cells excitable. closed under normal conditions; chemically regulated channels & voltage regulated channels |
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Term
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Definition
| cell changing charge; temporarily ends resting potential |
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Term
| chemically regulated channels |
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Definition
| active channels (closed under normal conditions); require a specific chemical, such as a neurotransmitter, to open them: neurotransmitter binds to receptor to open gate, & charge inside of cell changes--> creates action potential // MOTOR END PLATE of motor neuron |
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Term
| voltage regulated channels |
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Definition
| open/close when there is a change in charge across the membrane; closed at resting potential; open when charge inside cell goes from negative to positive (from resting potential to action potential) // synaptic knob, terminal cisternae, & sarcolemma |
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Term
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Definition
| stimulus to neuron--> VR (Ca) channel on synaptic knob releases Ca into neuron--> causes sarcolemma to break (?)--> synaptic vesicles rupture & expel acetylcholine (ACH) into neuro-muscular junction--> ACH binds receptor on motor end plate--> CR Na channels open--> influx of Na into muscle fiber--> depolarization of cell; membrane potential changes to more positive--> VR channels on terminal cisternae & sarcolemma open; Ca flows into cell (20% of Ca comes from extracellular space & 80% of Ca comes from within terminal cisternae) |
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Term
| plasma membrane of muscle fiber |
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Definition
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Term
| cytoplasm of muscle fiber |
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Definition
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Term
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Definition
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Term
| functional unit of skeletal muscle |
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Definition
| sarcolemma; occurs from z line to z line |
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