Motor control: spinal reflexes Flashcards
why are reflexes important
need to relay info for purposeful movement
how are reflexes classified
by type of nerve that transports it
where is motor spindle located
in parralled with striated muscle
what happens when spindle stretched
causes afferent AP>synapse on dorsal horn>alpha motor neuron AP
what 3 things occur when catch a dropped brick
- engage biceps
- engage other related flexors
- inhib. triceps
what is alpha-gamma coactivation
alpha- muscle fiber contraction
gamma - intrafusal fiber contracts spindle to maintain length
what is spindle afferent nerve type
1a
where is golgi tendon organ located
in tendon the muscle attaches to
what type of nerve is golgi tendon afferent
1b
what happens when 1b reflexes
synapses on interneuron>mixed other signals>inhibitory to muscle
what is withdrawal reflex
if step on something with right foot, will flex R and extend L to maintain balance
what is reversal of flexion reflex
because of descending motor commands, can result in opposed reflex actions
what happens to reflexes over successive trials
can increase or decrease them depending on what the situation calls for
what mediates the stumble reflex
skin afferents in the feet
