| Term: | floor plate secondary motor neuron |
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| Note: | This page represents a term created by the combination ("post-composition") of two ontology terms. For more information on the individual terms, click the hyperlinked name. |
| Name: | floor plate |
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| Synonyms: | floorplate, fp |
| Definition: | Multi-tissue structure that is the ventral-most aspect of the developing neural tube. The floor plate is a specialized glial structure with secretory function that spans the rostral-caudal axis from the midbrain to the tail regions. The floor plate is one of first structures that differentiate in the developing nervous system. |
| Ontology: | Anatomy Ontology [ZFA:0000022] |
| Name: | secondary motor neuron |
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| Synonyms: | secondary motoneuron |
| Definition: | Motor neurons that develop several hours later than primary motoneurons and sprout axons several hours after the primary motor growth cones have extended to the periphery. They have smaller cell bodies and are located more ventrally and laterally in the spinal cord than primary motoneurons. Axons usually project directly out of the spinal cord with no apparent contact with the Mauthner axon and are positioned lateral to the Mauthner axon in their path to the ventral root. Secondary motoneurons have smaller fields, which can overlap one another, and innervate many fewer muscle fibers than primary motoneurons. |
| Ontology: | Anatomy Ontology [ZFA:0009247] |