Final answer:
The reflex described in a 4-month-old infant who throws their arms out, spreads fingers, and grabs is known as the Moro reflex, not the rooting reflex. This protective response helps the baby to potentially cling to a caregiver, enhancing survival. The Moro reflex is different from the rooting reflex, which is related to feeding.
Step-by-step explanation:
The reaction you are describing in a 4-month-old infant, characterized by throwing arms out, spreading fingers, and grasping, is known as the Moro reflex, not the rooting reflex. The Moro reflex is an automatic response to a feeling of falling or a sudden loss of support. It typically lasts until the infant is about 3 to 4 months old and involves three components: spreading out the arms (abduction), pulling the arms in (adduction), and usually crying. This reflex serves as a protective measure and may aid the infant in holding on to their caregiver, thereby increasing the chances of survival.
On the other hand, the rooting reflex is an instinct that helps babies find a nipple or food source. When a baby's cheek is touched, the baby will turn toward the touch and open their mouth to feed. The rooting reflex, alongside the grasping reflex, are part of the various infant reflexes that play crucial roles in an infant's early development and survival.