Term
| List the steps of excitation-contraction coupling in skeletal muscle. |
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Definition
- Action potential is propagated along the sarcolemma and down the T tubules.
- Calcium ions are released.
- Calcium binds to troponin and removes the blocking action with tropomyosin.
- Contraction begins.
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Term
| List the steps of the cross bridge cycle in skeletal muscle. |
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Definition
- Cross bridge formation.
- The power (working) stroke.
- Cross bridge detachment.
- Cocking of myosin head.
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Term
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Definition
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Term
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Definition
| surrounds each muscle fiber |
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Term
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Definition
| surrounds each muscle bundle (fascicle) |
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Term
| Describe the deep fascia. |
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Definition
| binds muscles into functional groups |
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Term
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Definition
| plasma membrane of skeletal muscle fiber |
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Term
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Definition
| cytoplasm of a skeletal muscle fiber |
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Term
| Describe sarcoplasmic reticulum. |
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Definition
| series of membranous channels (modified ER) that surround each myofibril |
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Term
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Definition
| rod-like contractile elements within a muscle fiber |
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Term
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Definition
| functional unit of a skeletal muscle fiber |
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Term
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Definition
| area of a sarcomere with overlapping thin and thick filaments |
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Term
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Definition
| area of the sarcomere containing only thin filaments |
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Term
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Definition
| area in the center of the A band containing only thick filaments |
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Term
| Which molecule creates a cross bridge? |
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Definition
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Term
| Which area contains vesicles filled with acetylcholine? |
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Definition
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Term
| What is the space between the neuron and the muscle called? |
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Definition
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Term
| Which area contains receptors for acetylcholine? |
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Definition
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Term
| Which type of contraction is represented by a single stimulus/contraction/relaxation sequence? |
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Definition
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Term
| Which action involves a muscle producing peak tensions with visible relaxation during rapid cycles of contraction and relaxation? |
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Definition
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Term
| Which action involves a muscle that is stimulated so frequently that the relaxation phase is completely eliminated? |
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Definition
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Term
| Which action involves when a muscle is stimulated repeatedly for several seconds with a constant stimulus, the amount of tensions gradually increase to a maximum? |
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Definition
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Term
| Endurance-type activities are best suited for what type of fiber? |
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Definition
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Term
| A 400M or 800M sprint is best suited for what type of fiber? |
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Definition
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Term
| Short-term intense movements are best suited for what type of fiber? |
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Definition
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Term
| Define concentric contraction. |
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Definition
| contraction of the muscle in which the muscle shortens and does work |
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Term
| Define eccentric contraction. |
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Definition
| contraction of a muscle in which the muscle contracts as it lengthens |
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Term
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Definition
| neurotransmitter at the neuromuscular junction |
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Term
| What is creatine phosphate? |
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Definition
| high-energy compound in muscle |
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Term
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Definition
| oxygen storage molecules in muscle |
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Term
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Definition
| a product of anaerobic glycolysis |
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Term
| Which muscle fibers contract quickly and rely on aerobic respiration for ATP? |
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Definition
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Term
| Which muscle fibers are most resistant to fatigue? |
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Definition
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Term
| Which muscle fibers have few mitochondria? |
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Definition
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Term
| What is the time between the stimulus or the electrical event and the mechanical event of contraction called? |
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Definition
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Term
| What is the time during which the muscle is shortening called? |
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Definition
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Term
| What is the time during which the muscle is returning to its original length called? |
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Definition
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Term
| What is the very brief time after one stimulus during which the muscle is unresponsive to a second stimulus called? |
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Definition
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Term
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Definition
| propagation of an electrical current along the sarcolemma |
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Term
| Define resting potential. |
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Definition
| the initial polarized state |
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Term
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Definition
| restoration of membrane potential to resting potential |
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Term
| Define refractory period. |
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Definition
| the time when fiber cannot be stimulated until repolarization is complete |
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Term
| Define end plate potential. |
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Definition
| electrical event occurring only at neuromuscular junction |
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Term
| Define acetylcholinesterase. |
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Definition
| enzyme released into neuromuscular junction to break down acetylcholine |
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Term
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Definition
| cytoplasmic, calcium-binding protein |
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Term
| What are the electrical conditions of a resting sarcolemma? |
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Definition
| outside positive relative to the inside |
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Term
| What happens during depolarization and generation of action potential? |
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Definition
| production of an end plate potential at the motor end plate and consequent depolarization of adjacent areas |
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Term
| What happens during propagation of the action potential? |
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Definition
| increased positive charge inside sarcolemma changes the permeability of adjacent areas, opening voltage-regulated sodium ion channels |
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Term
| What happens during repolarization? |
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Definition
| change in sarcolemma after the wave of depolarization; sodium ion channels close and potassium ion channels open, allowing potassium ions to create a positive charge outside the membrane |
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Term
| What are the functions of skeletal muscle? |
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Definition
producing movement
maintaining posture
stabilizing joints
generation of heat |
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Term
| Which protein changes shape during the contraction cycle? |
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Definition
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Term
| Which protein slides toward the M line during contraction? |
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Definition
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Term
| Which protein covers the binding site? |
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Definition
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Term
| Which protein binds calcium ions and starts the contraction cycle? |
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Definition
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Term
| What is the ion released from the terminal cisternae that combines with troponin and removes the blocking action of tropomyosin, resulting in the formation of cross bridges? |
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Definition
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Term
| What binds calcium ions in a smooth muscle, causing contraction? |
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Definition
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Term
| What is the alternating contraction and relaxation of opposing layers of smooth muscle called? |
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Definition
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Term
| What happens during the initial stages of repolarization? |
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Definition
| electrical conditions are restored, ions are left unbalanced |
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