My Science School

A BABY GROWS

          It takes nine months for the fertilized egg to grow and develop in the mother’s womb, then become a baby ready to be born. This time is known as pregnancy. For the first eight weeks the developing baby is called an embryo. During this period, all of the main body parts and organs, such as the brain, heart, eyes, ears, and even the fingers and toes, form. At the end of eight weeks, the embryo is only about the size of a thumb-tip. But the main phase of development is complete and the baby looks like a miniature human being.

          For the next seven months the main change is in size. The baby grows at a faster rate than it will ever grow in the rest of its life. Finishing touches are added to the body, such as fingernails, toenails and eyelashes. During this growth phase the baby is known as a foetus.

EARLY DEVELOPMENT

          The part of the baby that develops fastest is the head, followed by the main body and then the limbs. In the early stages, the brain and spinal cord are by far the largest part of the body. During the fourth week, the main body begins to develop. The heart pumps blood through a simple system of tubes and the lungs begin to grow.

          Towards the end of the fourth week, the lower body organs, such as the intestine, liver and pancreas, form. The arms and then the legs also start to develop. At first they are tiny bumps on the body called limb buds, but they soon lengthen and the fingers and toes take shape.

          During the fifth week, the ears, eyes and nose take on more recognizable shapes. Main nerves begin to grow out from the brain and spinal cord. The kidneys and stomach also develop.

LIFE IN THE WOMB

          Inside the womb, the baby floats in a pool of amniotic fluid. The fluid cushions and protects it from bumps and jolts. The baby cannot breathe or eat in its watery surroundings. So it receives oxygen and nutrients from the mother through the placenta (also called the afterbirth). The baby can hear sounds such as its mother’s heartbeat. Loud noises from outside also pass into the womb and may startle the baby and make it jump. At first the baby has room to move and even turn somersaults. But as it grows larger it becomes more cramped, even though the womb stretches.

Picture Credit : Google