Session 4 Flashcards
a feedforward and feedback system among muscle spindles, golgi tendon organs, and joint receptors resulting in info about one’s muscle length and tension with resultant knowledge of one’s position in space
proprioception
a proprioceptor located within skeletal muscle providing constant feedback about changes in muscle length, muscle tension and muscle tone
muscle spindle (aka stretch receptor)
which type of muscle fibers are muscle spindles made of?
intrafusal muscle fibers
name the 2 types of muscle spindle sensory endings.
1a - primary endings
11 - secondary endings
a proprioceptor located at the junction of the muscle and tendon providing info about and detection of muscle tension or force in the tendon of a contracting muscle
golgi tendon organ (gto)
a specialized mechanoreceptor located in the joint capsule providing info about one’s position in space.
joint receptors
name 6 steps of sequences of muscle spindle activity.
- stretch occurs in skeletal muscle or extrafusal muscle fibers
- causes stretch of intrafusal muscle fibers or muscle spindle
- results in firing of 1a and II secondary endings
- proprioceptive sensory info proceeds into dorsal horn of the spinal cord.
- Ia and II fibers synapse with alpha motor neuron (AMN - aka lower motor neuron) in ventral horn of the spinal cord.
- then to one of 4 locations…
AMN of the same muscle AKA agonist muscle to facilitate muscle contraction
autogenic excitation
AMN of opposing muscle AKA antagonist muscle to inhibit muscle contraction
reciprocal inhibition
inhibit synergistic movement and allow isolated muscle control
renshaw cells
relay info about muscle length and position to regulate movement
tracts to cerebellum (Spinocerebellar and cuneocerebellar)
name the 1 GTO sensory ending.
Ib afferent endings
name 4 steps in the sequence of GTO activity.
- GTO detects muscle tension from contracting agonist muscle.
- info sent along Ib afferents into dorsal horn of spinal cord where Ib afferents synapse with interneuron.
- interneuron synapses with alpha motor neuron (AMN) in ventral horn of spinal cord.
- then to one of 3 locations…
inhibit contraction of same muscle aka agonist muscle
autogenic inhibition
name the 3 locations that GTO activity leads to.
- autogenic inhibition
- facilitate contraction of opposing muscle aka antagonist muscle
- to cerebellum to provide proprioceptive info about posture
name the 4 locations that muscle spindle activity leads to.
- autogenic excitation
- reciprocal inhibition
- renshaw cells
- to cerebellum to relay info about muscle length and position to regulate movement
name the 3 types of joint receptor endings
- ruffini endings
- pacinian corpuscle
- ligament receptor
stretch of joint capsule
ruffini endings