When observing an infant a few days we see that his days are divided between long periods of sleep, alternating with a few rare moments of watching, the child, by its nature, is more or less agitated. Infant sleep communicates a state of serenity unique, it is generally disturbed by the sensation of hunger at the approach of feeds.
The primary reactions or reflexes
A newborn baby is awake can do many things: seeing, hearing, taste, smell and movement. However, its behavior is largely governed by involuntary reflexes controlled by the lower part of the brain. The primary reflexes are the hallmark of brain functioning sub-corticospinal and their presence is physiological in the fetus and during the first months of life, indicating the absence of CNS depression and an intact brainstem but not reassuring on the integrity of higher brain. In fact, it was not until age 3 or 4 months that these reflexes are gradually converted into voluntary movements.
Sucking reflex
When he plays a caress, a newborn immediately turns his head toward the hand that touches his lips and then seek something to suck.
Non-nutritive sucking is also easy to analyze by placing a finger, curved downward, the middle part of the tongue, which only contact stimulates the sucking reflex.
The suction is not a continuous phenomenon and is composed of hot movements separated by an intermediate rest. In new-born at term, the number of sucking movements in a puff of 8 or more, the pace is fast and burst lasts 4 to 5 seconds and a strong negative pressure is seen (the finger is drawn) when the facial motor is normal, ensuring proper closure of the lips on the finger.
Automatic reflex walking
The child is held upright with one hand placed in the upper thoracic region. First we observe the recovery of the lower limbs and trunk, so that the child support for a few seconds a large part of the body weight. The child is then bent slightly forward, and a succession of steps is observed.
The automatic operation involves a rhythmic contraction of antigravity muscles triggered by skin contact of the foot. The newborn can climb stairs, but he can not go down: for we must bend down and bend requires greater control.
The lack of automatic operation is not a significant anomaly in the first days of life, because, very flexed posture in utero for a few days can make the extension difficult and painful.
This automatic operation is done on the soles of the feet in children and ultimately on tiptoe in children born prematurely.
Moro reflex
This reflex is called "defense". The child is supine raised a few inches by a slight pull on the two hands, upper limbs in extension. When his hands are suddenly released, it falls to the examination plan and reflex appears.
We obtain first:
- abduction of arms with extension of the forearms (opening of the first time) and complete opening of the hands;
- then a supply of arms and flex the forearm (embrace the second time).
Cry and anxiety in her eyes are part of the answer.
This reflex also appears if a baby is moved rapidly in space or on spilling his head back with a start. Sudden changes in the position startle.
Grasping reflex or grasping
When placing an index finger in the palm of the child, this simulation leads to a strong finger flexion. This maneuver can be made simultaneously on both sides and the sharp bending of the fingers can raise the child and bring him in a sitting position.
Crossed extension reflex
One foot is stimulated by rubbing the plant with the leg being held in extension. The response of the free leg to the stimulation was analyzed using three components:
- extension, after a rapid withdrawal movement in flexion
range of toes
- adduction that brings the free foot on the foot stimulated
Asymmetric tonic neck reflex (RTAC)
Reflex or fencer. Observed in the supine position with head rotation to one side: the occipital arm bent, arms extended facial.
There are other reflexes but looking for just a few.