8_Unit2.3_Somatosensation copy

sensitivity of the muscle spindle muscle spindle

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Unformatted text preview: l fibers extrafusal intrafusal at rest stretched GAmma system rests the spindle system!!!!!! Sensitivity of the muscle spindle •  Muscle spindle afferents respond to stretching of the intrafusal fibers extrafusal intrafusal contracted w/o γ at rest contracted w/ γ Action potentials it rests the retsing length of the muscle spindle while the muscle is contracted!!!!!!!! so it keeps tension on the muscle spindle ubder all conditions retard ass boi. Action potentials •  The gamma (γ) motor neuron increases the sensitivity of the muscle spindle 9 7/4/12 static--constant firing Static vs. Dynamic Sensitivity Static sensitivity refers to a receptor whose output (action potentials) maintains a constant frequency as long as the stimulus remains constant. State 1 Change Action potentials State 2 dynamic---increase or decrease in action potential prequency!!! TIME Dynamic sensitivity refers to a receptor whose output (action potentials) is altered (increased or decreased) by a sudden change of the stimulus. State 1 Change State 2 TIME Action potentials Some receptors have both static and dynamic sensitivity. statics- Static vs. Dynamic Sensitivity there is no change in firing its just a change in stste Muscle Static Muscle length Static Static Primary afferent Secondary afferent Action potentials TIME so this dynamic one is like the difference in the action pitentials between primary and secondary fferent-- Static vs. Dynamic Sensitivity Muscle primary --are velovities!!!!-- about change in state Dynamic (lengthen) Muscle length Dynamic Static (shorten) Static secondary is about state itself!! Static Primary afferent Secondary afferent Action potentials TIME 10 7/4/12 Static vs. Dynamic Sensitivity Muscle Dynamic (lengthen) Dynamic Static (shorten) Static Muscle length Static Primary afferent Secondary afferent Action potentials TIME Muscle Spindle and the Stretch Reflex Load applied to bicep muscle (cool refreshing beverage...
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This document was uploaded on 03/28/2014 for the course KNES 385 at Maryland.

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