unconditioned reflex

accommodation reflex - reflex changes in the eyes that enable an object to be focused on the retina

Babinski, Babinski reflex, Babinski sign - extension upward of the toes when the sole of the foot is stroked firmly on the outer side from the heel to the front; normal in infants under the age of two years but a sign of brain or spinal cord injury in older persons

belch, burp, burping, eructation, belching - a reflex that expels gas noisily from the stomach through the mouth

blink, blinking, eye blink, nictation, nictitation, winking, wink - a reflex that closes and opens the eyes rapidly

blush, flush - sudden reddening of the face (as from embarrassment or guilt or shame or modesty)

disgorgement, emesis, puking, vomiting, regurgitation, vomit - the reflex act of ejecting the contents of the stomach through the mouth

defecation reflex, rectal reflex - normal response to the presence of feces in the rectum

yawn, yawning, oscitance, oscitancy - an involuntary intake of breath through a wide open mouth; usually triggered by fatigue or boredom; "he could not suppress a yawn"; "the yawning in the audience told him it was time to stop"; "he apologized for his oscitancy"

electrical shock, shock, electric shock - a reflex response to the passage of electric current through the body; "subjects received a small electric shock when they made the wrong response"; "electricians get accustomed to occasional shocks"

breaking wind, farting, flatus, wind - a reflex that expels intestinal gas through the anus

gulping, gulp - a spasmodic reflex of the throat made as if in swallowing

response, reaction - a bodily process occurring due to the effect of some antecedent stimulus or agent; "a bad reaction to the medicine"; "his responses have slowed with age"

knee jerk, knee-jerk reflex, patellar reflex - a reflex extension of the leg resulting from a sharp tap on the patellar tendon

light reflex, pupillary reflex, miosis, myosis - reflex contraction of the sphincter muscle of the iris in response to a bright light (or certain drugs) causing the pupil to become smaller

mydriasis - reflex pupillary dilation as a muscle pulls the iris outward; occurs in response to a decrease in light or certain drugs

micturition reflex - relaxation of the urethral sphincter in response to increased pressure in the bladder

gag reflex, pharyngeal reflex - normal reflex consisting of retching; may be produced by touching the soft palate in the back of the mouth

goose bump, goose pimple, goose skin, goosebump, gooseflesh, horripilation, pilomotor reflex - reflex erection of hairs of the skin in response to cold or emotional stress or skin irritation

plantar reflex - flexion of the toes when the sole of the foot is stroked firmly on the outer side from the heel to the front in persons over the age of 2 years; under 2 years the results should be extension of the toes (Babinski reflex)

rooting reflex - reflex consisting of head-turning and sucking movements elicited in a normal infant by gently stroking the side of the mouth or cheek

startle, jump, start - a sudden involuntary movement; "he awoke with a start"

myotactic reflex, stretch reflex - reflex contraction of a muscle when an attached tendon is pulled; important in maintaining erect posture

suckling reflex - reflex behavior in newborn mammals; includes finding and grasping the nipple in the mouth and sucking on it and swallowing the milk

shiver, tremble, shake - a reflex motion caused by cold or fear or excitement

sneeze, sneezing, sternutation - a symptom consisting of the involuntary expulsion of air from the nose

hiccough, hiccup, singultus - (usually plural) the state of having reflex spasms of the diaphragm accompanied by a rapid closure of the glottis producing an audible sound; sometimes a symptom of indigestion; "how do you cure the hiccups?"