| Name: | primary motor neuron |
|---|---|
| Synonyms: | primary motoneuron |
| Definition: | Motor neurons that arise during the first day of development. Primary motoneurons have larger diameter cell bodies and axons than secondary motoneurons and are positioned more dorsally and medially than secondary motoneurons. Primary motoneurons are present in a single bilateral pair of clusters in each spinal segment and innervate axial muscle fibers in the corresponding pair of myotomes. Axons make a conspicuous loop around the Mauthner axon before entering the ventral root. |
| Ontology: | Anatomy Ontology [ZFA:0009244] |
| Name: | axonogenesis |
|---|---|
| Synonyms: | axon growth, axon morphogenesis, neuron long process generation |
| Definition: | De novo generation of a long process of a neuron, including the terminal branched region. Refers to the morphogenesis or creation of shape or form of the developing axon, which carries efferent (outgoing) action potentials from the cell body towards target cells. |
| Ontology: | GO: Biological Process [GO:0007409] QuickGO AmiGO |