15 Sep, 2007
Pregnancy Anatomy
Posted by: admin In: Uncategorized
Anatomy :
Once a month, an egg that is so small it is invisible to the human eye, is released from one of a woman’s ovaries, and travels down the Fallopian tube towards the womb (uterus). If during this journey, the egg encounters sperm released by the woman’s partner, the egg may be fertilised, and the woman falls pregnant.
Once penetrated by the sperm, the egg starts multiplying, from one cell to two, then four, eight, 16 and so on, doubling in size with each division. After ten days, the growing embryo consists of a fluid filled ball, only a couple of millimetres across. At this point it attaches to the wall of the womb and continues to grow, drawing all it needs from the mother through the placenta.
The placenta is a special outgrowth of the baby, that is firmly attached to the inside of the mother’s womb. It has blood vessels that penetrate into the womb wall, and interact with the mother’s arteries and veins to enable the baby to draw oxygen and food from the mother’s system, and send waste products to the mother for removal.
As the foetus (as the baby is known) grows, it floats in a fluid filled sack. It is like a water filled balloon, and the foetus drinks the fluid, and excretes into it through its kidneys and bowels.
One side of the balloon is especially modified into the placenta, while the rest is a fine but tough transparent membrane. The baby is connected to the placenta by the umbilical cord. At birth, this is about 80 cm. long, and runs from the belly button to the centre of the placenta, where the arteries and veins it contains fan out to interact with the mother’s circulatory system.