Structure: < Click on image >

Corticospinal Tract Termination. (Image modified with permission from drawings by C. Kaiser). Corticospinal tract fibers terminate in the gray matter of the spinal cord; most terminate on interneurons that synapse in turn on motor neurons (both alpha and gamma motor neurons). However, there are direct, monosynaptic, synapses on the most posterolateral motor neurons in the cervical spinal cord that move the fingers. Some corticospinal tract axons terminate in the posterior horn. The pattern of termination of corticospinal fibers depends upon their source; those from the motor cortices synapse in gray matter anteriorly, whereas those from the somatosensory cortices synapse posteriorly, in sensory relay nuclear regions.

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Software (C) 1997 <---> Images (C) 2000