Garbhasanskar

The embryo develops into a miniature human being. This stage begins on the 15th day after conception and continues until about the 8th week, or until the embryo is 1.2 inches in length. During this period the cells of the embryo are not only multiplying but are taking on specific functions. This process is called tissue differentiation It is during this critical period of differentiation (most of the first trimester or three-month period) that the growing fetus is most susceptible to damage from external sources (teratogens) including viral infections such as rubella. x-rays and other radiation, and poor nutrition. Formation of the heart begins in 3 weeks, the beginning development of the brain and spinal cord, and the beginning of the gastrointestinal tract. Beginnings of the vertebra, the lower jaw, the larynx (voice box), and the rudiments of the car and eye develop at weeks 4 and 5 (1/4 inch long). The heart, which is still outside the body, now beats at a re...