HOW BABY IS DOING: 5 weeks
THE DEVELOPING EMBRYO HAS 3 LAYERS. IN THE TOP LAYER, THE NEURAL TUBE WILL FORM WHICH WILL FURTHER DEVELOP INTO THE NERVOUS SYSTEM. IN THE MIDDLE LAYER, THE HEART AND CIRCULATORY SYSTEM, BONES, MUSCLES, KIDNEYS AND REPRODUCTIVE ORGANS WILL DEVELOP EVENTUALLY. AT THIS STAGE, HOWEVER, THE HEART AND PRIMITIVE CIRULATORY SYSTEM WILL RAPIDLY FORM. IN FACT, THE CIRCULATORY SYSTEM IS THE FIRST ORGAN SYSTEM TO FUNCTION. IN THE INNER LAYER, A SIMPLE TUBE WILL DEVELOP INTO THE INTESTINES, LIVER, PANCREAS AND BLADDER.