noun
unmyelinated nerve
Anatomical term for a nerve fiber that lacks a myelin sheath.
無髄神経は有髄神経より伝導速度が遅い。
Unmyelinated nerves conduct impulses more slowly than myelinated nerves.
有髄神経 is a myelinated nerve, which has a myelin sheath and faster conduction.
Compound of 無髄 (unmyelinated) and 神経 (nerve). The exact historical derivation is uncertain; the spelling is conventionally associated with the anatomical meaning.