Which reflex is elicited by a loud sound or a sudden drop, causing limbs to extend outward?

Which reflex is elicited by a loud sound or a sudden drop, causing limbs to extend outward?

• A. Moro (startle) reflex
• B. Grasping reflex
• C. Rooting reflex
• D. Babinski reflex

Answer: (A)

Recognizing a primitive newborn reflex triggered by a sudden stimulus. When a loud sound or a sudden drop occurs, a baby typically exhibits the Moro reflex: the arms extend outward and then move toward the body, often with crying, as if to grab for support. This pattern reflects a quick protective startle response and an immature nervous system; it usually disappears by about 4 to 6 months as motor pathways mature. Other listed reflexes describe different responses: the grasping reflex is a hand closure when the palm is touched; rooting is turning toward a cheek touch to find a nipple; and the Babinski reflex is toe extension with fanning in infants, which changes with age.

Recognizing a primitive newborn reflex triggered by a sudden stimulus. When a loud sound or a sudden drop occurs, a baby typically exhibits the Moro reflex: the arms extend outward and then move toward the body, often with crying, as if to grab for support. This pattern reflects a quick protective startle response and an immature nervous system; it usually disappears by about 4 to 6 months as motor pathways mature. Other listed reflexes describe different responses: the grasping reflex is a hand closure when the palm is touched; rooting is turning toward a cheek touch to find a nipple; and the Babinski reflex is toe extension with fanning in infants, which changes with age.