Neurological Basis of Movement Flashcards
What is a Renshaw cell?
An inhibitory interneuron found in the grey matter of the spinal cord.
How does a Renshaw cell work with an alpha motor neuron?
Alpha-motorneurones excite Renshaw cells causing them to release glycine back onto the alpha-motorneurone (inhibiting firing of the alpha-motorneurone) causing a negative feedback loop.
Synergistic muscles contract together to cause same movement.
How does Tetanus toxin affect Renshaw cells?
Tetanus toxin inhibits glycine release from renshaw cells
How does the Golgi tendon organ differ from the muscle spindle?
Golgi tendon organ has a higher threshold than muscle spindle
How is the Golgi tendon organ activated?
It is activated by prolonged stretch or contraction by Ib afferent axon.
How does an activated Golgi tendon organ work?
Produces inhibition of homonymous muscle, preventing damage to tendon.
What is the myotatic reflex?
The basic spinal reflex
Tap patellar ligament
• Stretches quadriceps muscle
• Stretches muscle spindle
• Activates Ia afferent
• Into spinal cord grey matter
• Excitatory synapse directly onto a-motor neuron which projects to homonymous muscle, which then contracts
• Excitatory synapse onto inhibitory interneuron which inhibits a-motor neuron that projects to heteronymous muscle, which then relaxes
What is the recurrent inhibition?
a
What is the inverse myotatic reflex?
a
