A Reflex Does Not Reach the Brain
A reflex is an involuntary response. The signal travels through the spinal cord and back without waiting for the brain.
A reflex is an automatic response to a stimulus. The speed comes from a shortcut: in a reflex arc, the signal travels to the spinal cord and back to the muscle without consulting the brain, which learns about it afterwards. That is why you withdraw your hand from something hot before you feel the pain.
- An involuntary response. *A knee-jerk reflex.*
- Reflective. *A reflex action.*
- Reflexive — referring back. *A reflexive pronoun.*
- Knee-jerk — automatic and unthinking. *A knee-jerk reaction.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | reflex | A slow reflex. |
| Plural | reflexes | Quick reflexes. |
| Adjective | reflexive | Reflexive verbs. |
| Related | reflect | Reflect the light. |
| Related | reflection | A clear reflection. |
How it is used in a sentence
- A reflex bypasses the brain.Travelling only to the spinal cord.
- A reflexive pronoun refers back.Myself, yourself, itself.
- Knee-jerk means unthinking.From the patellar reflex.
Common reflexes
- Patellar — the knee-jerk, tested with a hammer
- Withdrawal — pulling back from pain
- Pupillary — the pupil narrowing in bright light
- Startle — a whole-body response to sudden stimulus
- Reflex arc — sensory neuron, spinal cord, motor neuron
From Latin *reflexus*, bent back, from *reflectere*, from *re*, back, and *flectere*, to bend.
Why are reflexes so fast?
Because the signal goes only as far as the spinal cord and back, without the delay of processing in the brain.
What is a reflexive verb?
One whose action returns to the subject, usually taking a reflexive pronoun, as in *he hurt himself*.