THE MIRACLE OF HUMAN CREATION
to protect the sperm on its journey in the mother's body. For example, in the uterus various contractions and undulations occur. This uncommon activity in the uterus and fallopian tubes facilitates the sperm's advance towards the egg. The interesting thing about these contractions is the substance that causes them. This substance is called prostaglandin and is found in the seminal vesicle fluid that comes with the sperm from the male body. Despite the fact that it comes from a different body, this substance knows the structure of the mother's uterus and affects it in such a way as to make the way easier for the sperm.14 In order for fertilisation to take place, the changes that take place in the uterus are not limited to these. During this period the tubes expand; under the influence of the oestrogen hormones, the mucous membrane that lines the uterus increases in size and weight. The epithelial cells membranous tissues composed of one or more layers of cells separated by very little intercellular substance proliferate. This structure in the mucous assumes a shape that will permit the sperm to pass through these spaces with the movement of its tail. Besides allowing the sperm to move easily, this transformation has another very important function: the tissues serve as a storage and filter area, allowing only normal sperm to pass. Sometimes the sperm do not have a shape that can ensure fertilisation. In this case, they are suspended in these tissues. As can be seen from the foregoing, it is evident that every movement in
Sperm moving in the mucous