Definition

Noun: * Moro reflex: An involuntary, primitive reflex observed in healthy newborn infants, characterized by a startle response to a sudden stimulus such as a loud noise or the sensation of falling. The typical response involves the infant extending the arms and legs outward, then bringing them back toward the body, often followed by crying.

Usage

The term is used exclusively in medical, pediatric, and developmental contexts to describe a specific, normal neurological response in infants. * The pediatrician tested for the Moro reflex by gently lowering the baby's head. * The presence of a strong Moro reflex is a sign of a healthy nervous system in a newborn. * Parents often notice the Moro reflex when their infant is startled during sleep.

Advanced Usage

• Asymmetrical Moro reflex: A variation where the response is not equal on both sides of the body, which can sometimes indicate a neurological or orthopedic issue, such as a brachial plexus injury.
  • An asymmetrical Moro reflex prompted further investigation into a possible nerve injury.
• Integration of the Moro reflex: The process by which this primitive reflex diminishes and is controlled by higher brain centers, typically occurring between 3 to 6 months of age. Its persistence beyond this period may be noted in developmental assessments.
  • The therapist noted that the incomplete integration of the Moro reflex was contributing to the child's hypersensitivity to sound.

Variants and Related Words

• Startle reflex: A more general term sometimes used interchangeably with "Moro reflex," though it can refer to the startle response in individuals of any age.
• Primitive reflexes: A category of automatic movements, including the Moro reflex, rooting reflex, and grasp reflex, that are present at birth and originate in the brainstem.

Synonyms

• Startle reflex (in the specific context of infants)

Notes on Meaning

The Moro reflex is named after the Austrian pediatrician Ernst Moro, who first described it. It is considered a protective response. Its absence in a newborn or its persistence beyond the typical age range can be a clinically significant finding for healthcare professionals.

Noun

1. a normal reflex of young infants; a sudden loud noise causes the child to stretch out the arms and flex the legs