Final answer:
Reflexes such as the sucking, rooting, and grasping reflexes are vital for newborn survival, and the Babinski reflex is normal in infants but a sign of potential neurological issues in adults. A newborn's reflexes are often assessed during a neurological exam to establish proper lower motor neuron function. These assessments are part of the overall health evaluation, including the Apgar score, which is taken shortly after birth.
Step-by-step explanation:
Newborn Reflexes
Reflexes in newborns are instinctive behaviors that are crucial for the baby's survival, particularly before the advent of modern conveniences. These newborn reflexes are expected to serve essential functions in the early stages of life. For example, the sucking reflex allows infants to feed effectively from the mother's breast or a bottle, and the rooting reflex helps the baby locate the nipple. Another important reflex is the grasping reflex, which occurs when an object touches the palm and the baby instinctively grips it. This could have been significant for early human survival, possibly by helping the baby to cling onto the parent.
The Babinski reflex is particularly noteworthy. This reflex is seen when the sole of a newborn's foot is lightly scratched, causing the foot to dorsiflex and the toes to splay out. Although this response is normal and expected in infants, the presence of a Babinski reflex in adults can indicate neurological problems, such as reduced myelination in the spinal tract, which could make balance and coordination difficult. The transition of this reflex to a negative Babinski sign, where the toes curl upon plantar stimulation, corresponds with the acquisition of walking and is a sign of normal neurological development.
During a neurological exam, reflexes are assessed to determine the functionality of the lower motor neurons (LMN). The most common superficial reflex examined is the plantar reflex for the Babinski sign. As part of a comprehensive infant assessment, reflexes are also evaluated using criteria like those in the Apgar score, which assesses skin color, heart rate, reflex, muscle tone, and respiration right after birth.