Which of the following reflexes is most likely to be activated when something touches an infants palms?

Newborn reflexes, also known as baby reflexes or infant reflexes, are normal and are crucial for a baby’s survival. They are the baby’s muscle reactions, involuntary movements or neurological responses to stimulation or triggers which may include sound, light, sudden movement and being stroked or touched.

Doctors and nurses check baby reflexes to determine if a baby’s brain and nervous system are functioning properly. If you notice abnormal reflexes in your child, please see a doctor as these may indicate a dysfunction in the central nervous system.

There are many different types of newborn reflexes. You will notice many of them as you interact with your baby, and they can be really cute and fun to watch. Some reflexes only occur in specific periods of the baby’s development, but some can stay for years, all the way through adulthood. It’s good to note though that some adults who have brain damage or who have experienced stroke may experience baby reflexes as well.

1. Babies usually exhibit a full Moro reflex which includes the arms, head and legs in their first 12 weeks after birth. Also called the startle reflex, Moro reflex usually occurs when a baby gets startled by a loud sound, sudden movement or intense light. As a response to the trigger, the baby suddenly lifts the arms and legs, curl them back toward the body and then throw the head back. Your baby's own cry may also startle him/her and trigger the Moro reflex.

   Some babies experience an abnormal Moro reflex which only involves one side of the body. Other babies may have no Moro reflex at all. Some causes of an abnormal or absent Moro reflex may include infections, muscle weakness, injuries from childbirth, peripheral nerve damage and spastic cerebral palsy.

   When Does the Startle Reflex Go Away?

   The Moro or startle reflex usually lasts until the baby is about five to six months old.

2. This newborn reflex begins by touching or stroking the corner of the baby's mouth or when it touches the mother’s skin or nipple. When triggered, you will notice that the baby will turn his/her head and open his/her mouth to follow and "root" in the direction of the stroking. The rooting reflex helps the baby find the breast or bottle and also helps prepare him/her to suck.

   When Does the Rooting Reflex Go Away?

   The rooting reflex in babies usually lasts for about four months. After that, rooting becomes a voluntary response rather than a reflex.

3. This type of reflex usually starts when the baby is about 32 weeks inside the mother’s womb. If you’re pregnant, you may see your baby sucking his/her thumbs or hands during an ultrasound. When the baby is born, the sucking reflex happens in two stages. First, when the roof of the mouth is stimulated or when you place the mother’s breast or a bottle in his/her mouth, the baby will place the lips over the nipple and squeeze it between the tongue and roof of the mouth. Next, the baby will move his/her tongue to the nipple to suck and milk the breast.

   Premature babies may take weeks to properly suck and swallow which is why some doctors recommend a feeding tube inserted through the nose into the stomach to help them get the nutrients they need.

   When Does the Sucking Reflex Go Away?

   The sucking reflex usually lasts until the baby is four months old.

4. Also known as a fencing reflex, the tonic neck reflex happens when the baby's head turns to one side. This is triggered when you stroke or tap the side of the baby’s spine while the baby lies on his/her stomach. For instance, if the baby’s head turns to the right, the right arm will stretch out and then the left arm will bend at the elbow, forming a so-called "fencing" position.

   When Does the Tonic Neck Reflex Go Away?

   Tonic neck reflex may last until the baby is around five to six months old.

5. Stroking or touching the palm of a baby may cause the baby to automatically close his/her hands. For example, when you place your finger on the baby’s palm, he/she will grasp it and hold onto your hand because of the grasp reflex.

   When Does the Grasp Reflex Go Away?

   The grasp reflex may last until the baby is about five to six months old.

6. The Babinski reflex happens when you firmly stoke the sole of the baby’s foot. The baby’s big toe moves upward or toward the top of the foot and the other toe fans out.

   When Does the Babinski Reflex Go Away?

   The Babinski reflex usually lasts until the child is about two years old, but for some, it goes away after a year.

7. This cute reflex is also called the walking or dancing reflex. Stepping reflex happens when you hold the baby upright with his/her feet touching a flat surface. You will notice that the baby will move his/her legs as if he/she is walking or trying to take steps although the baby is still too young to actually walk.

   When Does the Stepping Reflex Go Away?

   The stepping reflex often lasts for about two months.

Please see a pediatrician in Detroit if you have worries about your baby’s development or if he/she continues to experience newborn reflexes beyond the normal period as this may be a sign of a nervous system dysfunction.

One of our pediatricians in Detroit may perform exams that can help determine if your baby experiences abnormal infant reflexes as well. If your baby was born prematurely, don’t compare his or her development to that of full-term newborns. Premature babies are usually behind full-term babies in terms of development.

The Moro reflex causes the baby to cry, throw back his or her head, and then pull his or her limbs into the body.

The tonic reflex is often called the "fencing" reflex because of the position of the hands.

Reflexes are involuntary movements or actions. Some movements are spontaneous and occur as part of the baby's normal activity. Others are responses to certain actions. Healthcare providers check reflexes to determine if the brain and nervous system are working well. Some reflexes occur only in specific periods of development. The following are some of the normal reflexes seen in newborn babies:

Rooting reflex

This reflex starts when the corner of the baby's mouth is stroked or touched. The baby will turn his or her head and open his or her mouth to follow and root in the direction of the stroking. This helps the baby find the breast or bottle to start feeding. This reflex lasts about 4 months.

Suck reflex

Rooting helps the baby get ready to suck. When the roof of the baby's mouth is touched, the baby will start to suck. This reflex doesn't start until about the 32nd week of pregnancy and is not fully developed until about 36 weeks. Premature babies may have a weak or immature sucking ability because of this. Because babies also have a hand-to-mouth reflex that goes with rooting and sucking, they may suck on their fingers or hands.

Moro reflex

The Moro reflex is often called a startle reflex. That’s because it usually occurs when a baby is startled by a loud sound or movement. In response to the sound, the baby throws back his or her head, extends out his or her arms and legs, cries, then pulls the arms and legs back in. A baby's own cry can startle him or her and trigger this reflex. This reflex lasts until the baby is about 2 months old.

Tonic neck reflex

When a baby's head is turned to one side, the arm on that side stretches out and the opposite arm bends up at the elbow. This is often called the fencing position. This reflex lasts until the baby is about 5 to 7 months old.

Grasp reflex

Stroking the palm of a baby's hand causes the baby to close his or her fingers in a grasp. The grasp reflex lasts until the baby is about 5 to 6 months old. A similar reflex in the toes lasts until 9 to 12 months.

Stepping reflex

This reflex is also called the walking or dance reflex because a baby appears to take steps or dance when held upright with his or her feet touching a solid surface. This reflex lasts about 2 months.

The presence and strength of a reflex is an important sign of nervous system development and function.

Many infant reflexes disappear as the child grows older, although some remain through adulthood. A reflex that is still present after the age when it would normally disappear can be a sign of brain or nervous system damage.

Infant reflexes are responses that are normal in infants, but abnormal in other age groups. These include:

• Moro reflex
• Sucking reflex (sucks when area around mouth is touched)
• Startle reflex (pulling arms and legs in after hearing loud noise)
• Step reflex (stepping motions when sole of foot touches hard surface)

Other infant reflexes include:

TONIC NECK REFLEX

This reflex occurs when the head of a child who is relaxed and lying face up is moved to the side. The arm on the side where the head is facing reaches away from the body with the hand partly open. The arm on the side away from the face is flexed and the fist is clenched tightly. Turning the baby's face in the other direction reverses the position. The tonic neck position is often described as the fencer's position because it looks like a fencer's stance.

TRUNCAL INCURVATION OR GALANT REFLEX

This reflex occurs when the side of the infant's spine is stroked or tapped while the infant lies on the stomach. The infant will twitch their hips toward the touch in a dancing movement.

GRASP REFLEX

This reflex occurs if you place a finger on the infant's open palm. The hand will close around the finger. Trying to remove the finger causes the grip to tighten. Newborn infants have strong grasps and can almost be lifted up if both hands are grasping your fingers.

ROOTING REFLEX

This reflex occurs when the baby's cheek is stroked. The infant will turn toward the side that was stroked and begin to make sucking motions.

PARACHUTE REFLEX

This reflex occurs in slightly older infants when the child is held upright and the baby's body is rotated quickly to face forward (as in falling). The baby will extend his arms forward as if to break a fall, even though this reflex appears long before the baby walks.

Examples of reflexes that last into adulthood are:

• Blinking reflex: blinking the eyes when they are touched or when a sudden bright light appears
• Cough reflex: coughing when the airway is stimulated
• Gag reflex: gagging when the throat or back of the mouth is stimulated
• Sneeze reflex: sneezing when the nasal passages are irritated
• Yawn reflex: yawning when the body needs more oxygen