primary motor neuron

Term ID

ZFA:0009244

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. 0471530506

Appears at

Segmentation:1-4 somites (10.33h-11.66h)

Evident until

Unknown

References

• CL:0000533
• TAO:0009244

Ontology

Anatomy Ontology