RUNNGING HEAD: The Prenatal Period
The Prenatal Period: 3 Stages and Drugs
Introduction to Psychology
The Prenatal Period last about nine months and consists of three different stages. The first stage is Germinal then Embryonic and finally the fetal stage. The baby goes through many different developmental changes during the prenatal period. Each stage brings new developments to a great bundle of life we call our baby.
Ovulation is the release of an ovum or egg from a woman’s ovarian follicle. During each menstrual cycle, several ovarian follicles begin to mature and develop but usually only one follicle develops fully. While the other follicles recede, the dominant follicle produces an egg that will be released and can be fertilized. The egg is picked by one of the fallopian tubes and begins to travel towards the uterus; this is where fertilization takes place. Fertilization must take place within the 12-24 hour lifespan of the egg after ovulation or the egg begins to degenerate and is no longer capable of being fertilized. Usually only a single ovum is released during ovulation. However if two separate ova are released and fertilized the result can be fraternal twins. It could be two brothers, two sisters, or a brother and sister. They are no more genetically alike than any other two children from the same parents because they come from two separate eggs. Identical twins can result if one ovum is released and split into two parts. Identical twins genes are almost indistinguishable. After ovulation the first stage of the prenatal period begins, called the germinal stage which begins at conception and last through the second week of pregnancy. About 2,000 sperm will reach the uterus and the fallopian tube. One of the sperm must attach itself to the ovum and penetrate its outer surface. The fertilized ovum, which is now called the zygote, will travel down the fallopian tube until it reaches the uterus. Then it attaches...
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