Term
| encapuslated receptors located at musculotendinous junctions in seriese with extrafusal fibers |
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Definition
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Term
| intertwined among these tendon fascicles are fine ________ terminal endings of large primary afferent fibers |
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Definition
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Term
| intertwined among these tendon fascicles are fine unmyelinated terminal endings of ______ ______ afferent fibers |
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Definition
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Term
| intertwined among these tendon fascicles are fine unmyelinated terminal endings of large primary _________ fibers |
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Definition
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Term
| in relaxed muscle, these nerve terminals within the tendon organs are not _________ or _______ |
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Definition
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Term
| What must occur for these specialized tendon fascicles to become taut |
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Definition
| muscle contracts and develops tension |
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Term
| What happens as a result of these specialized tendon fascicles becoming taut, |
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Definition
| they compress afferent nerve endings causing them to discharge |
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Term
| golgi tendon organs have _____ firing thresholds to tension caused by muscle shortenting |
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Definition
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Term
| golgi tendon organs have _____ firing thresholds to tension caused by muscle lengthening |
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Definition
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Term
| golgi tendon organs will always fiber in response to what type of motion |
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Definition
| muscle shortening, contraction |
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Term
| golgi tendon organs will not always fire to this type of action |
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Definition
| muscle lengthening/stretch |
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Term
| The adequate stimulus for tendon organ firing is development of tension by what type of muscles |
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Definition
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Term
| GTO's discharge frequencies are ______ to the active tension developed |
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Definition
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Term
| GTO's are referred to as ______ receptors |
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Definition
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Term
| Upon entering the spinal cord, central terminations divide into many terminal branches and synapse on small _______ and _______ interneurons in the spinal gray matter |
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Definition
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Term
| The GTO synapses onto the interneuron, which in turn synapse upon what |
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Definition
| motor neurons that innervate the same (homonymous) muscle |
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Term
| any increase in active muscle tension excites tendon organs whose signal, in turn, inhibits homonymous motoneurons whose activity caused the tension |
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Definition
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Term
| incoming signals that are inhibitory to motoneurons of one group of muscles, are at the same time excitatory to those of antagonists |
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Definition
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Term
| all skeletal muscle contains several.... |
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Definition
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Term
| muscle spindle neural input does not reach what |
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Definition
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Term
| one of the most complex receptors in the body |
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Definition
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Term
| Muscle spindles provide sensory feedback to the CNS about what depending on limb position |
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Definition
| absolute lengths of muscles |
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Term
| Muscle spindles provide sensory feedback to the CNS about what in regards to movement |
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Definition
| changes in muscle lengths |
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Term
| Muscle spindles provide sensory feedback to the CNS about what in regards to velocity of movement |
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Definition
| rates of change in muscle length |
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Term
| neural feedback from muscle spindles comprises a major component of the sensory input responsible for (4) |
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Definition
| motor control, motor coordination, kinesthetic sensation, proprioceptive sensation |
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Term
| how long are muscle spindles approximately |
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Definition
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Term
| each end of a muscle spindle attaches to what |
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Definition
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Term
| muscle spindle end attach to extrafusal muscle fibers with which they lie in _______ |
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Definition
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Term
| muscle spindles attach to extrafusal muscle fibers which means what in terms of length |
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Definition
| when one changes length, so will the other |
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Term
| with passive increases in muscle length, what happens to spindle firing? |
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Definition
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Term
| when muscle length decreases, what happens to spindle firing |
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Definition
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Term
| which muscles tend to be more involved in precise, skilled movements |
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Definition
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Term
| which muscles tend to be richer in spindles |
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Definition
| muscles involved in a precise skilled movements |
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Term
| which muscles tend to be less rich in spindles |
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Definition
| large proximal and trunk muscles |
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Term
| Muscles of which groups contain the highest number of spindles? (3) |
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Definition
| deep neck muscles, hands, feet |
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Term
| unlike most other receptors, muscle spindle sensitivity can be _______ |
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Definition
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Term
| how are adjustments made to muscle spindle sensitivity? |
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Definition
| motor system that functions in parallel |
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Term
| what is important to note about the motor system that controls muscle spindle sensitivity? |
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Definition
| independent from the motor system that controls extrafusal muscle fibers |
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Term
| muscle spindle sensitivity is controlled by what motor neurons |
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Definition
| gamme motoneurons/fusimotoneurons |
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Term
| what do gamma motorneurons innervate |
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Definition
| small muscle fibers called intrafusal muscle fibers |
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Term
| gamma motorneurons innervate intrafusal fibers that are found at _______ ends |
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Definition
|
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Term
| what are the 2 types of intrafusal fibers? |
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Definition
| nuclear bag, nuclear chain intrafusal fibers |
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Term
| how do nuclear bag and nuclear chain intrafusal fibers differ (3) |
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Definition
| morphologically, biochemically, functionally |
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Term
| muscle spindles have primary and secondary ________ endings |
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Definition
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Term
| muscle spindles contain two types of sensory-end organs _______ and _______ afferent endings |
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Definition
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Term
| which endings make firm and intimate contact with every intrafusal fiber within the spindle? |
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Definition
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Term
| which afferent endings make intimate contact around nuclear chain fibers but little/no contact on nuclear bag fibers |
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Definition
| secondary afferent endings |
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Term
| which afferent endings provide the CNS with information about velocity of movements? |
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Definition
|
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Term
| which fibers are implicated in velocity sensitivity of the muscle spindle |
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Definition
|
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Term
| why are nuclear bags implicated in the velocity sensitivity of the muscle spindle |
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Definition
| primary endings interact with nuclear bags, secondary do not. primary endings provide the CNS with information about velocity of movements |
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|
Term
| during passive stretch, what happens to muscle spindle discharge frequency? |
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Definition
|
|
Term
| during active shortening, what happens to muscle spindle discharge frequency |
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Definition
|
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Term
| even if the muscle is relaxed at resting length, which endings are continuously discharging |
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Definition
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Term
| primary endings are ________ discharging even if the muscle is relaxed at resting length |
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Definition
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Term
| primary endings are continuously discharging even if the muscle is.... |
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Definition
| relaxed at resting length |
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Term
| which ending does not show spontaneous activity? |
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Definition
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Term
| which endings decrease their discharge and show a short pause in their firing during an evoked isometric muscle twitch |
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Definition
| both primary and secondary endings |
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Term
| primary and secondary endings decrease their discharge and show a short pause in their firing during what |
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Definition
| evoked isometric muscle contraction |
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Term
| the pause that occurs during an evoked isometric muscle contraction occurs at the time that what occurs |
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Definition
| tendon organ has reached its peak firing rate |
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Term
| what is the adequate stimulus for primary and secondary endings? |
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Definition
|
|
Term
| at resting lengths, what endings fire? |
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Definition
|
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Term
| the response of the primary ending to passive stretch has what two component |
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Definition
|
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Term
| how does the firing rate of the primary ending compare during the dynamic/phase component than during the static phase when the muscle is being held at new length |
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Definition
| firing rate of the primary ending is higher during the dynamic/phasic component |
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Term
| frequency of firing during the dynamic phase of the stretch is proportional to what |
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Definition
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Term
| the phasic component of the response codes what information |
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Definition
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Term
| the static component codes information about what |
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Definition
|
|
Term
| which endings are slowly adapting receptors |
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Definition
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Term
| which endings provide the CNS with a continual input about muscle length |
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Definition
| the persistently active primary endings |
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Term
| primary spindle endings make what type of connection centrally? motor or afferent? |
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Definition
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Term
| central afferent connections from primary spindle endings make ________ synapses directly upon motorneurons innervating homonymous muscles in which the spindle lies? |
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Definition
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Term
| central afferent connections from primary spindle endings make excitatory synapses directly upon motoneurons innervating the same muscles in which the spindle lies. What is the type of circuit called? |
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Definition
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|
Term
| The reflex circuit serves what |
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Definition
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|
Term
| central connections from primary endings: afferents also diver to influence the _______ of other neurons at the same and distal spinal segments |
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Definition
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Term
| central connections from primary endings: afferents also diverge to influence the excitability of other neurons, such as afferents making excitatory connections with motoneurons innervating synergistic muscles and inhibtory connections with motoneurons of the antagonistic muscles through inhibitory interneurons. This is an example of what? |
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Definition
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Term
| In any stretch reflex, homonymous and synergistic muscles will function together unoppose because of what |
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Definition
| reciprocal inhibition of the antagonistic muscles |
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|
Term
| in addition to their spinal connections, muscle spindles project information to what else |
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Definition
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|
Term
| muscle spindles project information to the brain where it is integrated with information from other regions of the body to permit what |
|
Definition
| purposeful and coordinated movements |
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|
Term
| spindles have cortical representation, information from them appears to have no access to consciousness. T/F |
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Definition
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|
Term
| spindle input is thought to contribute to what sense |
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Definition
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|
Term
| spindle input is thought to contribute to position sense because joint position can be sense after what happens to cutaneous and joint receptors |
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Definition
| after they are anesthestized |
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Term
| spindle information projects to what part of the diencephalon and its neighbor? |
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Definition
|
|
Term
| why is spindle information projection to the cerebellum considered especially importnat? |
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Definition
| for the regulation of direction, extent, speed of movements |
|
|
Term
| small motor axons that terminate within the spindle capsule on the polar regions of the intrafusal muscle fibers |
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Definition
|
|
Term
| action potentials in gamma axons cause what |
|
Definition
| intrafusal muscle fibers to contract |
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|
Term
| what may innervate intrafusal fibers of more than one spindle |
|
Definition
|
|
Term
| with any on spindle a gamma axon will terminate on what |
|
Definition
| several intrafusal fibers |
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|
Term
| the brain receives information from the muscle spindle but it projects information back to the spindles via what |
|
Definition
|
|
Term
| if afferent input from muscle and joint receptors is distorted or abolished through injury or disease what happens |
|
Definition
| motor abnormalities result |
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|
Term
| What is the machinery that allows the nervous system to independently adjust the length sensitivity and the velocity of the muscle spindle? |
|
Definition
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