Descending spinal cord tracts signal spinal cord motoneurons for skeletal muscle. The actions is not direct to the motoneuron.

• Descending spinal cord tracts signal spinal cord motoneurons for skeletal muscle. The actions is not direct to the motoneuron.

• Most motoneurons are connected to descending pathways through interneurons.

• Fascilitory Interneurons (excitatory). These interneurons branch connecting to muscle for either agonist or antagonist muscle actions.

• Dysfacilatory Interneurons (inhibitory)

• Glycinergic Interneurons (inhibitory)
• GABAergic (inhibitory)
• When contractions occur in agonist, the antagonist must relax.

• Descending excitatory pathways- Corticospinal, Vestibulospinal, pontine reticular pathway

• Descending Inhibitory pathways- Reticulospinal tract.

• Combinations of excitation & inhibitions act thru interneurons serving to control patterned movements.