noun
spinal reflex
Medical/physiological term for an involuntary response mediated by the spinal cord. Also used figuratively for an immediate, unthinking reaction.
脊髄反射は、脳を介さずに起こる反応です。
A spinal reflex is a response that occurs without going through the brain.
彼の返事は脊髄
His reply was like a spinal reflex—immediate and unthinking.