Term: brain primary motor neuron
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: brain
Synonyms: brain structure
Definition: Cavitated compound organ which is comprised of gray and white matter and surrounds the cerebral ventricular system.
Ontology: Anatomy Ontology [ZFA:0000008]
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]