Spinal cord Flashcards
muscle synergy
coordinated muscular action
reciprocal inhibition
the inhibition of antagonist muscles during agonist contraction
- achieved by interneurons in the spinal cord
medially located pools in the spinal cord
innervate axial and girdle muscles
laterally located pools in the spinal cord
innervate distal limb muscles
posterior pools in the spinal cord
innervate flexor muscles
anterior pools in the spinal cord
innervate extensor muscles
phasic stretch reflex
response to the stimulus is brief
tonic stretch reflex
response last as long as the stimulus
myostatic reflex
same as phasic stretch reflex
–> from the muscle spindle(1a)–>dorsal horn–>ventral horn–>alpha motor neuron
- signal also goes to the cortex
3 actions to facilitate a contraction
1) quick stretch
2) tapping muscle
3) reflex
flexor withdrawal
occurs with you have a painful stimulus(hot stove)
- purpose is to pull the body away from painful stimulus to prevent tissue damage
- causes flexion
- nociceptive reflex
crossed extensor
- purpose is to keep you away from painful stimulus after flexor withdrawal(stepping back, hopping)
- allow time to develop new strategy to stay away
Lamina 1
marginal layer
- noxious stimuli
Lamina 2
substantia gelatinosa
- noxious stimuli
lamina 3 and 4
nucleus proprius
- proprioception and 2-point discrimination
lamina 5
noxious stimuli and info about viscera
lamina 6
proprioception info
lamina 7
nucleus dorsalis or Clarke’s column
- proprioception and relays unconscious proprioception
lamina 8
connect with the contralateral cord and brain
lamina 9
contains cell bodies of LMN’s
Lamina 10
axons crossing to the opposite side of the cord
stepping pattern generators
stepping by activating LMN’s, eliciting alternating flexion and extension at the hips and knees
reciprocal inhibition
decreases activity in an antagonist when an agonist is active
recurrent inhibition
inhibition of agonists and synergists, with disinhibition of antagonists