reflex
A very fast body reaction that happens without you thinking, for example when the doctor hits your knee and your leg moves.
An automatic, fast, and involuntary physical response of the body to a specific stimulus, controlled by the nervous system without conscious thought.
A way of acting or speaking that you do very quickly and without thinking, often because you have done it many times before.
An automatic, almost unconscious reaction or way of responding, especially one that is learned or habitual rather than purely physical.
Done very fast and without thinking, like an automatic reaction.
Describes an action, response, or movement that happens automatically and very quickly, without conscious thought or intention.
In language study, a newer sound or word that comes from an older sound or word in an earlier language.
In linguistics, a sound, word, or form in a language that has developed from a specific earlier sound, word, or form in an ancestor language.
- Base: reflex
- Plural: reflex, reflexes
blink reflex
1automatic eye blink to protect eyes
An automatic blink of your eyes that happens when something comes close to them or when they need protection.
- The doctor checked her blink reflex by moving a finger quickly toward her eye.
- Dust in the air can trigger your blink reflex to protect your eyes.
conditioned reflex
1learned automatic response to signal
An automatic reaction that you learn when a new signal is always paired with something that causes a reflex, like a sound before food.
- Pavlov's dogs developed a conditioned reflex and started to salivate when they heard a bell.
- A phone notification sound can create a conditioned reflex to check your screen.
gag reflex
1automatic choking-like throat response
An automatic reaction in your throat that makes you feel like you will choke or throw up when something touches the back of your mouth.
- The dentist was careful not to trigger my gag reflex.
- He has a strong gag reflex and cannot swallow large pills easily.
knee-jerk reflex
1automatic leg kick when knee tapped
An automatic leg movement that happens when a doctor gently hits the tendon just below your knee.
- The doctor tested her knee-jerk reflex with a small rubber hammer.
- A weak knee-jerk reflex can be a sign of nerve problems.
protective reflex
1automatic response that protects the body
A reflex that helps keep your body safe, like blinking to protect your eyes or coughing to clear your throat.
- Coughing is a protective reflex that clears the airways.
- The withdrawal of a hand from a hot object is a classic protective reflex.
reflex action
1automatic, unplanned body movement
A very fast body movement that happens by itself, without you deciding to do it.
- Pulling your hand away from a hot surface is a reflex action.
- Sneezing when something tickles your nose is a natural reflex action.
reflex arc
1nerve path of a reflex action
The path that nerve signals follow from the body to the spinal cord and back to the muscles to make a reflex action happen.
- The doctor explained how the reflex arc allows a fast response without involving the brain.
- Biology students drew diagrams of the knee-jerk reflex arc.
reflex hammer
1small hammer for testing reflexes
A small rubber hammer that doctors use to tap your body and check your reflexes.
- The neurologist picked up a reflex hammer to test the patient's knee.
- She had never seen a reflex hammer before her check-up.
stretch reflex
1automatic muscle tightening when stretched
An automatic tightening of a muscle when it is quickly stretched.
- The stretch reflex helps keep your posture stable when you stand.
- In physiology class, we learned how the stretch reflex protects muscles from injury.
unconditioned reflex
1inborn automatic response to stimulus
A natural reflex you are born with, not one you learn, like salivating when you taste food.
- Salivation in response to food is an example of an unconditioned reflex.
- Psychology students compared conditioned and unconditioned reflexes in animals.
vestigial reflex
1leftover reflex with little function
A reflex that comes from our past evolution and is still there, but does not have a clear use now.
- Goosebumps are often described as a vestigial reflex from when humans had more body hair.
- Some scientists consider the palmar grasp in adults a vestigial reflex.
startle reflex
1automatic jumpy response to sudden stimulus
A quick body reaction, like jumping or blinking, when you suddenly hear a loud sound or see something surprising.
- Newborns have a strong startle reflex when they hear loud noises.
- His startle reflex made him spill his drink when the balloon popped.
startle reflex
2Automatic reaction to sudden stimulus
A quick body movement that happens without thinking when you hear a loud sound or see something sudden.
- The doctor tested the baby's startle reflex by clapping hands.
- A loud noise can trigger your startle reflex.