• Reflexes
    Once the umbilical cord is severed, the newborn baby begins his independent existence. He can no longer rely on the nutritional support from his mother's womb. For the rest of his life, he will depend upon his own capacity to ingest and digest food. Fortunately, his life in utero has been a period of extensive preparation. As well as developing all the visible physiological structures common to the human species, the child has acquired an integrated nervous system that predisposes him towards certain forms of activity. These are the reflex mechanisms without which the infant would be unable to survive.

    Perhaps the best-known of these is the knee-jerk reflex. However, this is a spinal reflex and is of little direct importance to the neonate's survival. The greater interest of the reflex mechanisms associated with higher nervous functions in the brain, such as the sucking reflex.

    Sucking is one of the most immediately important skills that the neonate brings into the world. Without it he will be unable to survive except by intravenous feeding. Sucking is part of a whole complex of activities known as the "rooting" reflex. this includes turning the head towards the nipple, opening the mouth, grasping the nipple with the lips, sucking and swallowing. All of these activities have to be carefully coordinated if the child is to be successful in obtaining food. Even the task of locating the nipple is solved by the infant through a reflex mechanism. If you stroke either cheek on a newborn baby's face he will automatically turn towards the side you have touched. However, although sucking is functional from birth, it does need some environmental priming. Vigorous sucking may take three days to become properly established. The infant must learn to adapt to the various shapes of bottle (and breast) with which he is presented. In addition, he must accommodate his strength of sucking to the supply of milk available.

    As any mother will confirm, sucking occurs not only response to the presentation of a food supply. Neonates will suck at just about anything they can get between their lips. This is known as non-nutritive sucking. Even with no objects to mouth, the baby is likely to indulge in spontaneous mouthing, especially after feeding. Non-nutritive sucking seems to be controlled by an internal "clock" is the rate of sucking is fairly regular-about two sacks per second. Furthermore, infants with congenital mouth defects show no disturbance in regularity while in some brain injured infants the sucking rate shows marked irregularities. Sacking, then, is a centrally controlled, inborn capacity that is carefully organised for the purpose of food intake.

    There are many other reflexes which the infant brings into the world with him. Some are quite dramatic, such as the Moro, or startle reflex in which the infant spreads his arms apart as if in an attempt to protect himself. However, this reflex disappears soon after birth, as do many others, only to reappear under more conscious control later in development. Another remarkable capacity of the neonate is to grasp objects with his hands. If you stroke an infant's hand with your finger he will grasp hold of it tightly: so tightly in fact that it is possible to support him upright by allowing him to grasp hold of two of your fingers in either hand. One can imagine that in prehistoric times such a reflex might have been very adaptive for clinging on to the parents while they were on the move. Clearly such uses are inappropriate in modern society, but the grasping reflex does allow the infant to bring into contact a great variety of objects. His initial tendency to move his arms about in a haphazard way will ensure that the range of different objects will elicit the grasping response. He then has to learn to adapt that response to the different shapes and weights that he encounters.

  • Sleep
    Lorem ipsum dolor sit amet, sapien platea morbi dolor lacus nunc, nunc ullamcorper. Felis aliquet egestas vitae, nibh ante quis quis dolor sed mauris. Erat lectus sem ut lobortis, adipiscing ligula eleifend, sodales fringilla mattis dui nullam. Ac massa aliquet.