week 3-1 Flashcards
what is the function of the muscle spindle
muscle receptors that provide feedback to the CNS about muscle length and rate of change
what is alpha gamma coactivation
During a voluntary contraction, we activate both alpha MNs and gamma
MNs together so the spindle maintains its sensitivity during shortening
why does the tendon tap happen
spindle lengthen and la sensitive to stretch activate MN via Monosynaptic reflex
how do the GTO lie in the muscle fiber
series
GTO is the ____ afferent
Ib
function of the GTO
muscle receptors that provide feedback to the CNS about muscle force/tension
passive stretch
requires ~2 N; whereas
activation of single muscle fiber (30-90
millinewtons) can activate GTO
GTO sensitivity
Level of force necessary to excite a GTO
depends on mode of activation (muscle contraction)
what are GTO more sensitive to
actively generated forces than passive stretch
what do GTO respond to
increase muscle tension during a twitch
GTO provide motor feedback
Feedback to spinal cord via Ib afferent
Ib inhibitory interneuron
Disynaptic connection to motor neuron
Autogenic inhibition
Inhibits agonist motor neurons
Decreases force output
inhibit the agonist motor neurons
1.protective mechanism
2. monitor and modulate force control
location of the joint receptor
Within joint capsule, joint ligaments and loose articular tissue
– No receptors in cartilaginous surfaces of the joint, or in synovial
membranes
what do joint receptors respond to
Respond primarily at the limit of joint
movement (extremes)
- joint pressure
-both flexion and extension
