The Period Of Ovum - Conception to two weeks

This stage extends over a span of two weeks from the time of fertilization until the fertilized egg (now called the zygote) reaches the uterus. During this period, the foetus-to-be retains its egg-like appearance. Its size, which is no larger than a pinhead, remains practically unchanged because it receives no external nourishment. However, marked changes take place in the internal structure of the zygote. The single cell divides repeatedly until it forms a globular cluster of cells. The outer layer develops into accessory parts which protect and nourish the embryo. The inner cluster of cells later develops into the embryo itself. This cell division takes place as the fertilized ovum is carried down the fallopian tube to the uterus. Normally, fertilization occurs in the fallopian tube. When the zygote reaches the uterus it floats there for some tome before attaching itself to the uterine wall. It has to survive on the little yolk within the egg cell. When the ovum finds a place inside the uterus, it shoots out feelers which push their way through the blood vessels to tap nourishment. This process is called implantation and occurs about ten days after fertilization. Occasionally, the ovum does not move down to the uterus and becomes attached to the wall of the fallopian tube. This is called tubal Pregnancy and is a condition, which can endanger the mother’s life.