Which reflex is described as a sudden spreading of the arms when startled and then bringing them toward the midline?

Which reflex is described as a sudden spreading of the arms when startled and then bringing them toward the midline?

• A. Gag reflex
• B. Palmar grasp
• C. Sucking reflex
• D. Moro reflex

Answer: (D)

This question tests knowledge of primitive infant reflexes and their normal presentation. The described response—sudden spreading of the arms when startled followed by bringing them toward the midline—is the Moro reflex. Triggered by a startling stimulus such as a loud noise or a loss of support, the infant first extends and abducts the arms, then quickly adducts them toward the body as if embracing, often with crying. This reflex is present at birth and typically integrates by about 4 to 6 months as the nervous system matures. If it persists beyond that age or is asymmetrical, it can signal neurological issues. The other reflexes described are different: the gag reflex protects the airway, the palmar grasp involves fingers curling around a placed object, and the sucking reflex provides automatic sucking when something touches the lips.

This question tests knowledge of primitive infant reflexes and their normal presentation. The described response—sudden spreading of the arms when startled followed by bringing them toward the midline—is the Moro reflex. Triggered by a startling stimulus such as a loud noise or a loss of support, the infant first extends and abducts the arms, then quickly adducts them toward the body as if embracing, often with crying. This reflex is present at birth and typically integrates by about 4 to 6 months as the nervous system matures. If it persists beyond that age or is asymmetrical, it can signal neurological issues. The other reflexes described are different: the gag reflex protects the airway, the palmar grasp involves fingers curling around a placed object, and the sucking reflex provides automatic sucking when something touches the lips.