Moro reflex

Moro reflex
The Moro reflex in a four-day-old infant: 1) the reflex is initiated by pulling the infant up from the floor and then releasing him; 2) he spreads his arms; 3) he pulls his arms in; 4) he cries (10 seconds)

The Moro reflex, which is distinct from the startle reflex, is one of the infantile reflexes. It may be observed in incomplete form in premature birth after the 28th week of gestation, and is usually present in complete form by week 34 (third trimester). It is normally present in all infants/newborns up to 4 or 5 months of age, and its absence indicates a profound disorder of the motor system. An absent or inadequate Moro response on one side is found in infants with hemiplegia, brachial plexus palsy, or a fractured clavicle. Persistence of the Moro response beyond 4 or 5 months of age is noted only in infants with severe neurological defects. It was discovered and first described by Austrian pediatrician Ernst Moro (1874-1951).

This reflex is a response to a sudden loss of support, when the infant feels like it is falling. It is believed to be the only unlearned fear in human newborns[citation needed]. The primary significance of this reflex is in evaluating integration of the central nervous system (CNS), and it involves 3 distinct components:

  1. spreading out the arms (abduction)
  2. unspreading the arms (adduction)
  3. crying (usually)

Absence of any component (except crying) or any asymmetry in the movements is abnormal, as is persistence of the reflex in older infants, children and adults. However, in individuals with cerebral palsy, persistence and exacerbation of this reflex is common.


1. Adams and Victor's Neurology, Chapter 28. Normal Development and Deviations in Development of the Nervous System

External links

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Moro reflex — mȯr ō n a reflex reaction of infants upon being startled (as by a loud noise or a bright light) that is characterized by extension of the arms and legs away from the body and to the side and then by drawing them together as if in an embrace Moro …   Medical dictionary

  • Moro-Reflex — Der Moro Reflex (Klammerreflex, Umklammerungsreflex) tritt bei Jungtieren vieler Säuger auf. Er wurde nach den dem Arzt Ernst Moro benannt, der den Reflex 1918 beschrieb.[1] Moro Reflex bei einem vier Tage alten Säugling Beim Menschen führt das… …   Deutsch Wikipedia

  • Moro reflex — startle reflex a primitive reflex seen in newborn babies in response to the stimulus of a sudden noise or movement: the baby will fling its arms and legs wide and will appear to stiffen; the arms and legs are then drawn back into flexion. The… …   The new mediacal dictionary

  • Moro reflex — /ˈmɒroʊ ˌriflɛks/ (say moroh .reefleks) noun a reflex present in newborn babies in which the arms and legs convulsively straighten when the child is startled and feels that he or she is being dropped. Also, Moro response …   Australian English dictionary

  • Moro reflex — noun a normal reflex of young infants; a sudden loud noise causes the child to stretch out the arms and flex the legs • Syn: ↑startle reflex • Hypernyms: ↑startle, ↑jump, ↑start …   Useful english dictionary

  • Moro-Reflex — Mo̱ro Re|flex: Umklammerungsreflex, Neugeborenen und Säuglingen bis zum vierten Lebensmonat eigentümliche Reflexbewegung des Umklammerns mit den Armen bei Er schrecken, plötzlicher Lageveränderung u.Moro Reflexä …   Das Wörterbuch medizinischer Fachausdrücke

  • Moro — bezeichnet: Moro (Sprache), eine Sprache in Afrika eine Sorte Blutorangen, siehe Orange (Frucht) Modellvorhaben der Raumordnung, ein Aktionsprogramm des Bundesamts für Bauwesen und Raumordnung Moro Reflex, ein frühkindlicher Reflex Moros (Volk),… …   Deutsch Wikipedia

  • Moro — Contents 1 Events 2 Groups 3 Languages 4 People …   Wikipedia

  • Reflex — A reaction that is involuntary. The corneal reflex is the blink that occurs with irritation of the eye. The nasal reflex is a sneeze. * * * 1. An involuntary reaction in response to a stimulus applied to the periphery and transmitted to the… …   Medical dictionary

  • Reflex — For other uses, see Reflex (disambiguation). A reflex action, also known as a reflex, is an involuntary and nearly instantaneous movement in response to a stimulus.[1] A true reflex is a behavior which is mediated via the reflex arc; this does… …   Wikipedia