Definition of muscle spindle in English:

muscle spindle

Pronunciation /ˈmʌsl ˌspɪndl/

noun

Anatomy Physiology
  • A fusiform bundle of specialized muscle fibres with sensory and motor innervation enclosed in a capsule of connective tissue, present in large numbers in skeletal muscle and sensitive especially to stretch.

Origin

Late 19th century; earliest use found in Journal of Physiology. From muscle + spindle, after German Muskelspindel.