Proprioception Flashcards
_______ comprise the main bulk of
skeletal muscle, which generate force during
muscle contraction
extrafusal fibers
each extrafusal fiber is part of a motor unit that is
innervated by a particular ______
alpha motor neuron
level of activation of each extrafusal fiber
is determined by the ______ it
receives from the alpha motor neuron
strength of signaling
strength of signaling from alpha motor
neurons is determined through _______of the multiple inputs
synaptic
integration
the functional state of a muscle is dependent on what two properties
length and active tension
_____ determines joint angles
and/or angles of joint rotation
muscle length
_____ provides counteracting
force against the external load to stabilize
joint positions
active tension
A functional state of a muscle, reflects a ______ between muscle activation, and load against the muscle
continuous interaction
Determined by the accumulation of signals (excitatory/inhibitory) that provide input to alpha motor neurons innervating the the muscle
level of muscle activation
To establish proper length and tension of a muscle requires sensory awareness that is provide by what kind of peripheral receptor
proprioceptive receptors
What are the two proprioceptors in muscles
Muscle Spindles
Golgi Tendon Organ
Intrafusal muscles are innervated by what kind of neuron
gamma motor neuron
Golgi tendon are located where
in muscle tendons
Reports muscle length and changes in length
Muscle splindles
What depolarizes muscle spindle fibers
stretching of the muscle
_____ from the sensory neurons is proportional to the amount of stretch
rate of firing
What are the two different types of intrafusal fibers found with muscle spindles
Nuclear bag fibers
Nuclear Chain fibers
Large diameter, myelinated, fast conducting afferent fibers
Type Ia
Intermediate diameter, meylinated, relatively fast conduction afferent
Type II
____ fibers are slowly adapting and mainly report static length
Type II
____ fibers are rapidly adapting and mainly report changes in length
Type Ia
_____ modulates the sensitivity of muscle spindles to length and changes in length
Fusimotor system
Respond to dynamic phase of stretch
Dynamic gamma mot neurons
Respond to static phase of stretch
Static gamma motor neurons
What happens if a muscle spindle becomes unloaded
muscle spindles may stop signaling
Why is co-activation of gamma and alpha motoneurons needed
to prevent muscle spindles from becoming unloaded
What enhances the stimulus of the muscle
Fusimotor system
Reports force and tension generated by muscle
Golgi tendon organ
Golgi tendon organs give rise to what kind of afferent fibers
Type Ib afferent fibers
Output from the golgi tendon organ is____ in proportion to the amount of stretch to the nerve ending
Graded
Muscle spindles and golgi tendon organ provide input for what reflexes
spinal motor reflexes
A stereotypic motor response to a particular sensory input
Motor Reflex
____ reflex in response to input from muscle spindles
Myotatic reflex
____ reflex in response to input from Golgi tendon organs
Inverse myotatic reflex
The myotatic reflex provides ____ inputs to alpha motor neurons in response to muscle lengthening
Excitatory inputs
Reflex contributes to stabilization of muscle length by activating muscle shortening
Myotatic reflex
The inverse myotatic reflex provides ____ inputs to alpha motor neurons in response to increase in muscle tension
inhibitory inputs
Reflex contributes to stabilization of muscle tension by releasing muscle tension
inverse myotatic reflex
The sensory feedback provided by myotatic and inverse myotatic reflexes serve to create balance between what?
Agonists and antagonists muscle pairs
______ innervation contributes to appropriate balancing between agonist and antagonists
Reciprocal innervation
