Term
| Maximal force potential of a muscle is proportional to the sum of what? |
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Definition
| Cross-sectional area of all the fibers and the pennation angle. |
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Term
| If muscle fibers attach parallel to a tendon what is the pennation angle and how much of the muscle force is transmitted to the tendon? |
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Definition
| 0 degrees, and all of the force is transmitted. |
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Term
| T/F. Pennate muscles produce greater maximal force than fusiform muscles of similar size? |
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Definition
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Term
| What are the connective tissues that surround the muscles? |
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Definition
| Endomysium, Epimysium, Perimysium. |
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Term
| T/F Connective tisues are slightly plastic and are incapable of generating resistive force? |
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Definition
| False. They are elastic and are capable of generating resistive forces when elongated. |
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Term
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Definition
| Stretching a muscle by extending a jiont elongates both the parallel elastic component and the series elastic component, generating a springlike resistance, or stiffness, in the muscle. |
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Term
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Definition
| The muscle length at which passive tension begins. |
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Term
| T/F Passive tension stabilizes skeletal structures against gravity and responds to perturbations and other imposed loads. |
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Definition
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Term
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Definition
| Ability of the muscle to sotore part of the energy that created the inital stretch of the muscle. |
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Term
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Definition
| Rate-dependent resistance encountered betweent the surfaces of adjacent fluid-like tissues. |
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Term
| T/F Since viscosity is time dependant then a muscle will respond with greater internal resistance with a high rate of stretch. |
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Definition
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Term
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Definition
| occurs in skeletal muscle from a single stimulus from a motor nerve. |
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Term
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Definition
| mechanical responses to successive stimuli are added to an initial response. |
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Term
| Which myofilament contains the cross-bridge? |
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Definition
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Term
| T/F. The amount of active forcea muscle can generate is independant of the instantaneous length of the muscle fiber. |
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Definition
| False. The active force a muscle is capable of generating is dependant on the instantaneous length of the muscle. |
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Term
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Definition
| Length that allows the greates number of cross-bridge attachments and, therefore, the greates otential active force. |
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Term
| At shortened lengths, below active resting length, and below the length that generates passive tension, what force dominates the force generating capability of the muscle? |
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Definition
| Active force. No passive tension is involved here. |
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Term
| At what point does passive tension begin to contribute so that the decrement in active force is offset by increased passive tension? |
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Definition
| At any length beyond the active resting length of the muscle. |
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Term
| T/F. The amplitude of an isometrically produced force from a given muscle reflects only the length-dependent active force. |
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Definition
| False. Isometrically produced forces from a muscle reflect the summation of both length-dependent active and passive forces. |
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Term
| What is the biggest factor in determining the "rate of change of length" for a muscle? |
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Definition
| The muscle's maximal force potential. |
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Term
| T/F. In eccentric activation, an increase in load will cause a decrease in muscle lengthening? |
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Definition
| False. An increase in load will increase the rate of change. A decrease in load will decrease the rate of lengthening. |
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Term
| T/F. on a theoretical force-velocity curve, during a maximal concentric activation the muscle force is inversely proportional to the velocity of muscle. |
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Definition
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Term
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Definition
| Rate of work. can be expressed as a porduct of force times contraction velocity. |
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Term
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Definition
| THE sequence of driving moto-neurons to higher rates which modulates muscle force. |
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Term
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Definition
| Refers to the initial activatin of a specfic set of motoneurons resulting in gthe generation of action potentials that excite target muscle fibers. |
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Term
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Definition
| The orderly activatino of motoneurons starting from smallest to largest, resulting in smooth and controlled force development. |
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Term
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Definition
| Slow, oxidative. Slow and show relatively little fatigue (loss of force during sustained activation). generally smaller motoneurons |
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Term
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Definition
| Fast and glycolytic fast and easily fatigued. |
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Term
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Definition
| Intermediate motor units that are between slow and fast type motor units. Combined use of oxidatie and glycolytic energy sources. |
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Term
| Time length of action potential and muscle fiber contraction |
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Definition
| Action potential:1-2 ms. Muscle fiber contraction: 130 ms. |
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Term
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Definition
| Occurs if an action potential arrives at a muscle before a preceding twitch has relaxed, causing the twitches to summate and generate an even greater level of force than an isolated twitch. |
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Term
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Definition
| a set of repeating action potentials, sparated by a suitable time interval, generates a series of summated mechanial twitches. |
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Term
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Definition
| As the time interval shortens between twitches the successive peaks and valleys of mechanical twitches fuse into a single, stable level of muscle force. Represents the greates force level that is possible for a muscle fiber. |
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Term
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Definition
| The decline in muscle force under conditions of stable activation. |
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Term
| T/F. The nervous system will compensate of muscle fatigue by increasing the rate of activation (rate coding) |
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Definition
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Term
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Definition
| Affected by psychological factors, such as sense of effort, neurophysiological factors, like descending control over interneurons and motoneurons located in the spinal cord. |
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Term
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Definition
| FActors related to action potential propagation in motor nerves and transmission of activation to muscle fibers. |
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Term
| Repetitive activation of motor units can result in a gradual reduction of acetylcholine release. What kind of fatigue is this? |
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Definition
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