Phenotype: primary motor neuron degenerate, abnormal
Note: This statement combines anatomy and/or ontology terms with phenotype quality terms to create a complete phenotype (EQ) statement. For detailed information on individual terms, click the hyperlinked term name.
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: degenerate
Synonyms: degeneration
Definition: A structural quality inhering in a bearer whose structure deteriorates or is lost over time due to an active pathological process.
Ontology: Phenotypic Quality Ontology [PATO:0000639]