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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
so it keeps tension on the muscle spindle ubder all
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 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
(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
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
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This document was uploaded on 03/28/2014 for the course KNES 385 at Maryland.
- Fall '08